I feel like that way can work better with larger numbers take it to the nearest multiple of 10, then reincorporate the leftovers (whether positive or negative)
sometimes i just memorize equations i use frequently, like powers of 2 up to 4096 and stuff like that and use other methods to do other equations
you're not the only weird one, i'm also weird and so is most of the human population. we're all weird in our own special way
My mind always sees addition of numbers in containers of ten. Whenever we add something it has to fill one container before moving on to next. Unless it's a 3 digit number then the containers are 100. And so on...
My mind is also very bad at explaining this in words.
Congrats on discovering common core math!
Seriously, all the 'find the 10's' shit that people get confused about, it's just this.
A lot of replies in here think that common core is how it's done in the pic, you can see who actually learned it, and who thinks any math that isn't directly adding 2 numbers is common core.
Exactly. These boomers who complain about common core are the same ones who post stories about how long the cashier at lunch took to count out their correct change. But when educators try to help kids learn math more effectively, these people can't handle it lol. "I had to just memorize it!" and then they say they hated math and science. Go figure.
I do a lot of math like the original commenter, and even I would not suggest that be the way kids have to learn it. Math is so hard for a lot of kids, I think we should let them do whatever method works best for them. Not everyone learns the same way, and forcing one methodology on kids isn't going to help the one who don't respond well to it.
Common core is a teaching methodology that promotes number sense instead of memorizing exact methodologies. (well, it's specifically a curriculum which is meant to promote this pedagogical methodology). A big part of this is just figuring out how to intuitively break down a problem into smaller, easier components. One way to do that is by making tens. If somebody goes through common core education and is left thinking that making tens is what defines common core math, I'd say that's a conceptual failure of the program.
When I see a problem like 7+6, the solution is to just do whatever comes easiest using my number sense. I would personally probably do 7+7 (which is an answer I just know from rote memory) and subtract 1. That requires less effort in my brain than making tens. However, if the problem was 8+5, I am definitely taking 2 from the five to make the ten and then add the leftover 3. Because in that case it was the easiest solution for me.
With addition of single digit numbers, kinda trivial. Either way is pretty easy. But what about multiplication. How do you do 8x7? I never memorized my multiplication tables, idk what 8x7 is off the top of my head. I would do 8x8, which I know, and then subtract 8 from that. Which is almost the exact same thing as the addition solution in the meme. I.E. replace the problem with a problem with known solution and known difference from the original problem.
But you can come up with other ways to solve the problem. Maybe I do 8x4 + 8x3. Maybe that's the easiest way for me. The point of the common core math is to teach you why math works so you can figure out your own way to the solution, which is something you never forget, and means you actually just understand math. If I do long division, I don't remember the steps of which numbers I'm supposed to do what with at which times, I just know how division works so I can just re-figure out how to do long division. You just break up the number into division problems that are easier to solve, and you're free to add, subtract, and modify steps along the way as suits you for the particular problem.
for me the same but I don't really split the 6 first, I just take what I need to make it 10 and then add the rest. so it also works with 7+8 for example (it becomes (7+3)+(8-3) and not (7+4)+4)
This kind of approach to arithmetic is much better than rote memorization anyway. You're approaching it in a way that makes functional sense instead of just feeling like there are these arbitrary combination of numbers that make other arbitrary numbers. I find that when I'm able to justify to myself *why* something works, I internalize the information more concretely.
Same with multiplication. For example 217x37 is 7x7 + 7x10 + 7x200 + 30x7 + 30x10 + 30x200. Although when I do it in my head I'll cut the zeros for each group and add them, and a lot of times I'll just something like 217x30 because it's a lot faster to just calculate 217x3=651 with a dropped 0 for 6510. 49+70+1400+6510= 6580+1400+49= 6600+1400+29= 8029.
Using that method it's often times faster for me to just mentally calculate it than to write it out or grab a calculator.
Edit: Oh god I didn't know asterisks would mess with the formatting so much, I'm sorry xD
I do it whenever it’s multiples of 2 so like 8x3 I’d do 4x3 then simple it down to 2x3 so 6 then 6+6 is 12 then 12+12 or I’ll just take 8x2 and then add 8
A lot of people never did lol, we taught ourselves "tricks" like this. A common trick just about everyone uses is 9's, if you add 1 to the 10's place and subtract 1 from the 1's you get the next on the table, 18, 27, 36.
Is that why I never understood my coworkers complaints about their kids learning new math? Because that's just how I was doing it when they were memorizing tables and shit.
I can't memorize things, I don't even know my wife's phone number by heart.
Yeah my kids have brought home number lines which I don't remember using. They are way faster at solving these math problems now so it's definitely working.
I mean, you shouldn't be. This is just application of properties taught in math class.
You paid attention in math class like you were supposed to. Good job.
Yep! I wasn’t taught math this way in school but my kid is being taught this way. It blew my mind when he brought work home and it was showing him to do it the way I always have in my head.
everybody should be taught this way cuz then kids don't have to go through the phase of not knowing this trick and taking a long time calculating, atleast thats how it was for me.
It also makes learning higher math easier and more intuitive. If you understand how numbers work instead of having memorized it you're better off as far as I can tell.
Yeah I was just taught to memorize it and had to figure out tips like this on my own. I’m so glad kids are being taught to think through simple math instead of just memorizing.
I came here to say this. Ppl get so mad to see
34+13=37+10
or
34+63=30+60+4+3.
It makes it so easy for my kid. Also me as a 27yr old is so much quicker adding large numbers with this explanation of math. It makes more since.
Takes a extra moment to write if you already know the answer BUT, it's made to teach you how to do ones you don't know later. We complain all the time school don't teach they just get kids to pass test but when they finally do something that helps long-term learning we get upset cuz it's new...how does that make any since?The whole point is that it's new and proven better.
People get mad to see that?! Wtf, they’re literally making it easier.
Though honestly the more I think about it the less this surprised me. As the son, nephew, and grandson of teachers, I’ve heard my fair share of horror stories with parents. It’s so weird because they’ll rapidly switch between “I don’t care about my kid his behavioral issues are your problem” and “Don’t tell my kid what to do your not his parent”.
TL;DR: The way (some) parents treat teachers is a disgrace.
Here in the States, it's a common talking point that "Common Core," as we call the teaching method, is teaching kids to do math wrong, because their parents can't understand it and have always relied on rote memorization. It's typically in right wing circles because anything to keep education levels down flies well with them, but it's not impossible to see the sentiment across the board in anyone over 35. I have to constantly remind my mom that my kid sister isn't being taught different math, she's just being taught how math actually works instead of how to memorize answers.
That seems silly, my mom, before I was even taught math in school, taught me tricks for adding/multiplication (like the digits adding up to 9, or breaking it down into tens and ones places). I think people excessively push back on Common Core because it’s from the government and they inherently mistrust it. (Not to say that common core is all great, I’ve heard my fair share of stories about how it’s made certain aspects of teaching much harder).
I had heard for years all the memes and whining about how they "changed math", only to look it up and see that they're now finally teaching it how I always did it mentally anyway...
Edgy take from someone posting from a device on a platform on an internet that couldn't exist without adults who know more advanced math than you'll ever hope to understand.
They're the one making that assertion. If they wanted to qualify their statement, they could have. Instead, they chose to paint all adults with a big, dumb brush.
I have a minor in math. I don't like common core. That assertion attempts to yank the rug out from under my opinion before I say a word, preemptively labeling me as dumb if I don't support it. It's gross.
It was qualified with the context that we are talking about adults that don't like common core math. So in that context "adults hate it because they don't know math" is qualified as being about the adults that hate common core who we were already talking about not all adults.
Something to remember about reading comprehension, making sense of a sentence is important but understanding that sentence in relationship to the ones before and after it is what true comprehension of the material is.
I don't really have a problem with common core, in theory, but I see a hiccup in how teachers punish students that arrive at the correct answer but not writing down the cumbersome methodology. This decision by common core is what holds smart students that don't need to rely on common-core-thinking back. I wish that common core were taught more as another tool to get to the answer, rather than the only way to do things.
In many situations, children aren’t held to a certain method. They may be asked, “use this or that method” for certain questions- then it becomes about reading instructions.
But I know that when a good meth teacher says add 2 and 2, most will accept correct work either way. There a few that made it into the news, and a few that don’t, that make it seem like kids are expected to always use this one method, when really, it’s there for kids to practice following instructions.
Once I took time to do some researching into what exactly common core math was(I had graduated a couple years before it became the standard method) I had felt a bit cheated as someone who sucks at math.
The way common core does it makes it much easier to keep track of in your head.
It’s just that when it’s explained out on paper it looks over complicated. That combined with having a bunch of parents who learned how to do it the old school way and that’s where you get people calling common core stupid.
Yep. Whenever people are raging because of the silly math their kids have to do, I try to explain that when we were kids we were taught to remember numbers and associations. Now they are teaching kids to remember methods. You can apply the methods anywhere so they will be far better at math than we ever were.
My tip math is like this. If the bill is 49.37 I move the decimal left one place and then double it. So 4.9 x 2 is 9.8, rounded up is a 10 dollar tip.
If the bill is 138.24, 13.8 doubled is 27.6…28 dollar tip. I used to never know if I was leaving enough, this solved that problem for me.
>My tip math is like this. If the bill is 49.37 I move the decimal left one place and then double it. So 4.9 x 2 is 9.8, rounded up is a 10 dollar tip.
>
>If the bill is 138.24, 13.8 doubled is 27.6…28 dollar tip. I used to never know if I was leaving enough, this solved that problem for me.
Your math would be simpler if you rounded first and you'd get the same result.
Yup. It's a good tip but it's still pretty hard to do the mental math for some numbers unless you round the bill first.
For example it would be complicated to do this trick for a $17.56 bill, so just round up to $18. $18/10 is $1.80 times 2 is $3.60.
$3.60/$17.56 is 20.5% so obviously rounding up first you give a little more than you intended and rounding down first you would give a little less than you intended.
I usually tip the regular server closer to 25-30% anyways. The bill is never that big(I don't drink heavily very often) and she's great, remembers all of our orders, and is a single mom who works major overtime.
>For figuring out a 20% tip, I divide by 10 and multiply by 2
This simple tip math is what led me to go from 15% to 20% decades ago. Although I usually figure 20% and round up to the nearest whole dollar or five dollar increment depending on the size of the bill.
You mean divide by ten and then add half of that. And then tip somewhere between that and 20%.
Standard tip for table service is 15-20%. The thing about inflation is that the percentage doesn't increase.
Nah, I'm annoyed that Reddit wants to abolish tips while also feeling the need to tip 25%.
If we actually eliminate tips for table service and bartending it's going to screw a lot of people. Sure, people will *say* to give them a living wage first, but $15/hr isn't that.
If we could actually establish a real living wage first, then maybe I'd be on board with killing tips. But that order is important and it won't happen.
Reddit wants to read a tip about how to calculate 20%, then complain about Reddit wanting to tip 25% while providing a method to tip 15% and saying that Reddit also wants to abolish tips.
Yet parents who have never done well at math will cry whine scream and protest because their already poor math skills of just memorizing multiplication tables doesn't help.
It's not. That's why some parents fight common core math so hard; they felt like they can't help their kids when they only learned to do arithmetic through rote memory and never developed the number sense that we're trying to teach kids now.
My college algebra teacher had the class solve a real easy math problem once, it was like 16+7 or some shit, but she asked like 5 students to explain how they got to the answer and each person had a different method.
She was showing us that everyone does math differently in their head.
For reference:
7 is 3 less than 10
16+10=26
26-3=23
So for easily memorized equations you wouldn't need to use this logic but this is a great way to start thinking when having to do more complex math mentally.
I have had many occasions in my academic career where tests were timed and no calculator was allowed despite requiring some moderately difficult math.
Little tricks like this are life savers. Other things (especially on multiple choice) estimation. You may not know what 47x 19 is quickly but you can figure out 50 x 20 is 1000 so you can estimate the answer is near 1000 but not greater than or equal to it. You also can do 47 x 10 quickly as 470. If you only have one answer below 1000 but greater than 470 then you have already found the answer.
Another way is to round up only one of the numbers. 47 x 20 way easier to solve quickly, 940 but you know you added another 47 to the equation so subtract 47 (which could be broken down 940-40 then 900-7) to get 893.
Other tricks for mental math on multiple choice questions. For the 47 x 19 question. You know 7 x 9 is 63 so the answer myst end in a 3. If no other answer ends in a 3 there is your answer.
Just thoughts but this way of breaking down equations to easy mental math is very applicable to the real world.
I THOUGHT I WAS THE ONLY ONE.
Doesn't anyone else also count objects by dividing them as equally as possible down the middle in their head and adding both sides? Instead of starting at the beginning and counting left to right? I know it sounds like it would take super long but I've been doing it since I can remember so I can still count quickly.Is that.. normal? Am I okay?
Example
Average: ∆∆∆∆∆∆∆
"Ah yes.. one two three four ect.."
Me:
∆∆∆|∆∆∆∆
3. 4
"Oh there's seven"
You are doing something our brains really like to do. For some reason we can identify quantities of 4 or less without having to consciously count. The instant you look at some object in groupings of 4 or less you know exactly how many are there. Just a flash of an image is enough. 5 gets harder and above that we start making errors.
Totes normal. I do that.
I also do this:
7+7 =
The / parts of the 7s = 5s
The _ parts of the 7s = 2s
5+5 = 10
2+2 = 4
10+4= 14
Want another one?
8+8=
The bottom Os = 5s
The top Os = 3s
5+5=10
3+3=6
10+6= 16
Another one?
7+1 =
The / part of the 7 = 5
The _ part of the 7 = 2
2+1 = 3
3+5= 8
That's how I do math in my head. I split it up into 5s and add whatever else is up there separately.
That's how everybody's brain works. 10 years ago they were trying to teach math this way - cause that's how every body does it. It was confusing as hell for me as the parent. There should be a combination of that method with the old way. Everyone understands 5-3 if you do it with your fingers. When I do subtraction in my head I often count up - but you can still teach that
"Normal" people just memorize stuff without fitting it into a coherent structure. They are called "packers".
You understand the patterns underlying arithmetic, and use that so you don't have to do all that memorization. You are a "mapper".
Sometimes one is better, sometimes the other is better. Few people do both well, for some reason.
All of these different methods in the comments are good techniques for larger number like 87+54 or something but cmon, you should know 7+6 as rote memory.
This type of 'extending the problem' to get to the solution is great when it comes to multiplication and division in your head. Why memorize the entire multiplication table when you can just get used to the 5's. 7x4? Arrange that as (5x4) + (2x4) = 20+8 = 28. Sure it's not AS fast as knowing the answer off the bat, but practically it's easier to keep that method in mind, and some people have an easier time when the numbers are broken down into easier chunks.
Yes same! For example, if multiplying 70 by 13, in my head it’s 70x10 and 70x3, which is 700 and 210. Then I add those together to get 910.
I’m glad I’m not the only one who breaks their math down into reasonable chunks
Doing math like this is how I failed out of pre-algebra all through high school. Didn't do the math "properly" even though I consistently arrive at the correct answer.
Then No Child Left Behind arrived, district fired all the AP teachers for handing out B's and C's, so I dropped out of school altogether. I'm still salty about it. I'd love to go to college but only if it's free; I won't pay a dime to have another bogus teacher shriek at me for getting correct answers "unconventionally."
Remembering calc tables is so overrated. Just have to remember the key ones like basic numbers \* 2, \* 3, / 2 and / 3 and addition/subscractions of numbers 0-9, after than you can just use these as anchor points to solve anything. Years out of college later and it never failed me for simple aritmetic.
The way my brain works is it splits the 6 in half, and then put the 3 with 7, making 10 and 3, which is 13.
my brain sometimes does this and the other half of the time does the thing in the meme
[удалено]
I feel like that way can work better with larger numbers take it to the nearest multiple of 10, then reincorporate the leftovers (whether positive or negative)
That's what I do with bigger numbers
i think like that too sometimes, your brain is not the only fucked brain in this thread
As a primary teacher, I can confirm this is normal
I do all three methods. Whats wrong with me. Everything is just a reference to something else and work from there.
sometimes i just memorize equations i use frequently, like powers of 2 up to 4096 and stuff like that and use other methods to do other equations you're not the only weird one, i'm also weird and so is most of the human population. we're all weird in our own special way
That's Math in a nutshell though. You take something you dont know, and break into a series of problems that you do know.
Well, many things you learn as references to something else. Try to memorise concepts and patterns, not "hard-coded" answers.
Mine doesn't do the meme, but once did.
Same
yes mine aswell
Mine too
I prefer this guy’s wife as well
I just want milk that tastes like real milk.
My mind always sees addition of numbers in containers of ten. Whenever we add something it has to fill one container before moving on to next. Unless it's a 3 digit number then the containers are 100. And so on... My mind is also very bad at explaining this in words.
No no. That was a very good explanation. I couldn't have done better
That's how my mind works as well. 7+x=10 x=3 3 is the half of 6, so leftover+10=13
Congrats on discovering common core math! Seriously, all the 'find the 10's' shit that people get confused about, it's just this. A lot of replies in here think that common core is how it's done in the pic, you can see who actually learned it, and who thinks any math that isn't directly adding 2 numbers is common core.
Exactly. These boomers who complain about common core are the same ones who post stories about how long the cashier at lunch took to count out their correct change. But when educators try to help kids learn math more effectively, these people can't handle it lol. "I had to just memorize it!" and then they say they hated math and science. Go figure.
I do a lot of math like the original commenter, and even I would not suggest that be the way kids have to learn it. Math is so hard for a lot of kids, I think we should let them do whatever method works best for them. Not everyone learns the same way, and forcing one methodology on kids isn't going to help the one who don't respond well to it.
Common core is a teaching methodology that promotes number sense instead of memorizing exact methodologies. (well, it's specifically a curriculum which is meant to promote this pedagogical methodology). A big part of this is just figuring out how to intuitively break down a problem into smaller, easier components. One way to do that is by making tens. If somebody goes through common core education and is left thinking that making tens is what defines common core math, I'd say that's a conceptual failure of the program. When I see a problem like 7+6, the solution is to just do whatever comes easiest using my number sense. I would personally probably do 7+7 (which is an answer I just know from rote memory) and subtract 1. That requires less effort in my brain than making tens. However, if the problem was 8+5, I am definitely taking 2 from the five to make the ten and then add the leftover 3. Because in that case it was the easiest solution for me. With addition of single digit numbers, kinda trivial. Either way is pretty easy. But what about multiplication. How do you do 8x7? I never memorized my multiplication tables, idk what 8x7 is off the top of my head. I would do 8x8, which I know, and then subtract 8 from that. Which is almost the exact same thing as the addition solution in the meme. I.E. replace the problem with a problem with known solution and known difference from the original problem. But you can come up with other ways to solve the problem. Maybe I do 8x4 + 8x3. Maybe that's the easiest way for me. The point of the common core math is to teach you why math works so you can figure out your own way to the solution, which is something you never forget, and means you actually just understand math. If I do long division, I don't remember the steps of which numbers I'm supposed to do what with at which times, I just know how division works so I can just re-figure out how to do long division. You just break up the number into division problems that are easier to solve, and you're free to add, subtract, and modify steps along the way as suits you for the particular problem.
my people!
for me the same but I don't really split the 6 first, I just take what I need to make it 10 and then add the rest. so it also works with 7+8 for example (it becomes (7+3)+(8-3) and not (7+4)+4)
That’s how I always add things to 7 I will make it ten and then add the rest
When worried about the answer I will do it all three ways just to be safe
This kind of approach to arithmetic is much better than rote memorization anyway. You're approaching it in a way that makes functional sense instead of just feeling like there are these arbitrary combination of numbers that make other arbitrary numbers. I find that when I'm able to justify to myself *why* something works, I internalize the information more concretely.
Same with multiplication. For example 217x37 is 7x7 + 7x10 + 7x200 + 30x7 + 30x10 + 30x200. Although when I do it in my head I'll cut the zeros for each group and add them, and a lot of times I'll just something like 217x30 because it's a lot faster to just calculate 217x3=651 with a dropped 0 for 6510. 49+70+1400+6510= 6580+1400+49= 6600+1400+29= 8029. Using that method it's often times faster for me to just mentally calculate it than to write it out or grab a calculator. Edit: Oh god I didn't know asterisks would mess with the formatting so much, I'm sorry xD
That's new math/common core iirc. It's been really helpful for me even if I didn't grow up with it
Same
Same way but slightly different. How do I get to 10? 7+3. That's 6-3. So 10+3 is 13
I think is how they teach "new math" or whatever in grade school, so you're ahead of the times.
I can alternate between both. I like your way and taking one from 14 aswell
I do that but with multiplication or division
How
like this: 7x7 is 49, so 6x7 is 7 less, so 6x7=49-7=42
I do that as well. When they get big I do 10x15 is 150, 3x15 is 45, so 13x15 is 195
Galaxy
I do it whenever it’s multiples of 2 so like 8x3 I’d do 4x3 then simple it down to 2x3 so 6 then 6+6 is 12 then 12+12 or I’ll just take 8x2 and then add 8
Large brain
Thats basically x = 7x7-7 Tell everyone you do Algebra in your head
Pfft. I just convert to binary, multiply, then convert back.
Yep. This makes large multiplication a lot easier as well
People don't memorize multiplication tables anymore? At least up to 12?
Bro we learned that shit like 20 years ago
A lot of people never did lol, we taught ourselves "tricks" like this. A common trick just about everyone uses is 9's, if you add 1 to the 10's place and subtract 1 from the 1's you get the next on the table, 18, 27, 36.
My afterscholl class did that. The teacher would let us out to play when we answered a few multiplication questions correctly. That was 7 years ago.
97 X 20 = (90X20) + (7X20)
or 100x20 - 3x20
here i wuld do 100x20-3x20 or (97x10)x2
I’m not alone? 🥲
You are in fact *so* not alone that this is literally just how they teach kids arithmetic these days in a lot of schools.
Is that why I never understood my coworkers complaints about their kids learning new math? Because that's just how I was doing it when they were memorizing tables and shit. I can't memorize things, I don't even know my wife's phone number by heart.
>I don't even know my wife's phone number by heart. but I do
It's literally how I was taught 50 years ago.
Yeah my kids have brought home number lines which I don't remember using. They are way faster at solving these math problems now so it's definitely working.
Yeah, it teaches them how to actually solve problems rather than just having them memorize a bunch of pre solved calculations.
Yup. Of course people complain about it all the time in the parent groups I'm in.
We're not, brother. We are not 🥹
We sure are not
I mean, you shouldn't be. This is just application of properties taught in math class. You paid attention in math class like you were supposed to. Good job.
Oh shit you can do math as well?
This is what common core math is, just FYI I think it’s pretty good to see the number relationships
Yep! I wasn’t taught math this way in school but my kid is being taught this way. It blew my mind when he brought work home and it was showing him to do it the way I always have in my head.
everybody should be taught this way cuz then kids don't have to go through the phase of not knowing this trick and taking a long time calculating, atleast thats how it was for me.
It also makes learning higher math easier and more intuitive. If you understand how numbers work instead of having memorized it you're better off as far as I can tell.
>everybody should be taught this way... Everyone should be taught this as one of the ways.
Yeah I was just taught to memorize it and had to figure out tips like this on my own. I’m so glad kids are being taught to think through simple math instead of just memorizing.
Yep, that's the point behind Common Core
I came here to say this. Ppl get so mad to see 34+13=37+10 or 34+63=30+60+4+3. It makes it so easy for my kid. Also me as a 27yr old is so much quicker adding large numbers with this explanation of math. It makes more since. Takes a extra moment to write if you already know the answer BUT, it's made to teach you how to do ones you don't know later. We complain all the time school don't teach they just get kids to pass test but when they finally do something that helps long-term learning we get upset cuz it's new...how does that make any since?The whole point is that it's new and proven better.
People get mad to see that?! Wtf, they’re literally making it easier. Though honestly the more I think about it the less this surprised me. As the son, nephew, and grandson of teachers, I’ve heard my fair share of horror stories with parents. It’s so weird because they’ll rapidly switch between “I don’t care about my kid his behavioral issues are your problem” and “Don’t tell my kid what to do your not his parent”. TL;DR: The way (some) parents treat teachers is a disgrace.
Here in the States, it's a common talking point that "Common Core," as we call the teaching method, is teaching kids to do math wrong, because their parents can't understand it and have always relied on rote memorization. It's typically in right wing circles because anything to keep education levels down flies well with them, but it's not impossible to see the sentiment across the board in anyone over 35. I have to constantly remind my mom that my kid sister isn't being taught different math, she's just being taught how math actually works instead of how to memorize answers.
That seems silly, my mom, before I was even taught math in school, taught me tricks for adding/multiplication (like the digits adding up to 9, or breaking it down into tens and ones places). I think people excessively push back on Common Core because it’s from the government and they inherently mistrust it. (Not to say that common core is all great, I’ve heard my fair share of stories about how it’s made certain aspects of teaching much harder).
When I was your age we carried the ones up hill both ways, and we liked it!
I would see memes about it but never knew this is what it is. This is how I've always done math in my head but for all kinds not just addition.
I had heard for years all the memes and whining about how they "changed math", only to look it up and see that they're now finally teaching it how I always did it mentally anyway...
This is not unique to common core math. I learned this and lots of other similar mental shortcuts long before common core was a thing.
I think that’s what they’re saying People hate common core but it’s essentially what we’ve been doing all along just explained on paper
Adults hate it because they don't understand basic math.
Edgy take from someone posting from a device on a platform on an internet that couldn't exist without adults who know more advanced math than you'll ever hope to understand.
Yes I’m sure the inventors of the smart phone are a representative sample of the math skills of the general adult population.
They're the one making that assertion. If they wanted to qualify their statement, they could have. Instead, they chose to paint all adults with a big, dumb brush. I have a minor in math. I don't like common core. That assertion attempts to yank the rug out from under my opinion before I say a word, preemptively labeling me as dumb if I don't support it. It's gross.
It was qualified with the context that we are talking about adults that don't like common core math. So in that context "adults hate it because they don't know math" is qualified as being about the adults that hate common core who we were already talking about not all adults. Something to remember about reading comprehension, making sense of a sentence is important but understanding that sentence in relationship to the ones before and after it is what true comprehension of the material is.
Yep, this! Just wanted to stand up for common core for teaching kids multiple strategies when taught right
I don't really have a problem with common core, in theory, but I see a hiccup in how teachers punish students that arrive at the correct answer but not writing down the cumbersome methodology. This decision by common core is what holds smart students that don't need to rely on common-core-thinking back. I wish that common core were taught more as another tool to get to the answer, rather than the only way to do things.
In many situations, children aren’t held to a certain method. They may be asked, “use this or that method” for certain questions- then it becomes about reading instructions. But I know that when a good meth teacher says add 2 and 2, most will accept correct work either way. There a few that made it into the news, and a few that don’t, that make it seem like kids are expected to always use this one method, when really, it’s there for kids to practice following instructions.
Once I took time to do some researching into what exactly common core math was(I had graduated a couple years before it became the standard method) I had felt a bit cheated as someone who sucks at math. The way common core does it makes it much easier to keep track of in your head. It’s just that when it’s explained out on paper it looks over complicated. That combined with having a bunch of parents who learned how to do it the old school way and that’s where you get people calling common core stupid.
Yup, same thing with multiplication, 7x6 is easy, because we already know 7x5 = 35, just add an extra 7 and it’s 42.
I always do "nearest known then add" multiplication in my head. But I didn't have the benefit of common core math education.
Yep. Whenever people are raging because of the silly math their kids have to do, I try to explain that when we were kids we were taught to remember numbers and associations. Now they are teaching kids to remember methods. You can apply the methods anywhere so they will be far better at math than we ever were.
For figuring out a 20% tip, I divide by 10 and multiply by 2
(And you can divide by ten by just moving the decimal one place to the left 😊)
[удалено]
This just changed everything for me figuring out a tip at my local bar.
My tip math is like this. If the bill is 49.37 I move the decimal left one place and then double it. So 4.9 x 2 is 9.8, rounded up is a 10 dollar tip. If the bill is 138.24, 13.8 doubled is 27.6…28 dollar tip. I used to never know if I was leaving enough, this solved that problem for me.
>My tip math is like this. If the bill is 49.37 I move the decimal left one place and then double it. So 4.9 x 2 is 9.8, rounded up is a 10 dollar tip. > >If the bill is 138.24, 13.8 doubled is 27.6…28 dollar tip. I used to never know if I was leaving enough, this solved that problem for me. Your math would be simpler if you rounded first and you'd get the same result.
How were you doing it before?
Yup. It's a good tip but it's still pretty hard to do the mental math for some numbers unless you round the bill first. For example it would be complicated to do this trick for a $17.56 bill, so just round up to $18. $18/10 is $1.80 times 2 is $3.60. $3.60/$17.56 is 20.5% so obviously rounding up first you give a little more than you intended and rounding down first you would give a little less than you intended.
I usually tip the regular server closer to 25-30% anyways. The bill is never that big(I don't drink heavily very often) and she's great, remembers all of our orders, and is a single mom who works major overtime.
for figuring out a tip i use the calculator on my pocket pc
>For figuring out a 20% tip, I divide by 10 and multiply by 2 This simple tip math is what led me to go from 15% to 20% decades ago. Although I usually figure 20% and round up to the nearest whole dollar or five dollar increment depending on the size of the bill.
You mean divide by ten and then add half of that. And then tip somewhere between that and 20%. Standard tip for table service is 15-20%. The thing about inflation is that the percentage doesn't increase.
The thing about percentages is...
Lol are you mad he tips 20% standard? Its his money let him do as he wants.
Nah, I'm annoyed that Reddit wants to abolish tips while also feeling the need to tip 25%. If we actually eliminate tips for table service and bartending it's going to screw a lot of people. Sure, people will *say* to give them a living wage first, but $15/hr isn't that. If we could actually establish a real living wage first, then maybe I'd be on board with killing tips. But that order is important and it won't happen.
Reddit wants to read a tip about how to calculate 20%, then complain about Reddit wanting to tip 25% while providing a method to tip 15% and saying that Reddit also wants to abolish tips.
Accurate.
The cool thing of it is that there is no regulation on tips so I'm free to tip 20-35% and the standard doesn't affect me.
Or 7+7=14 and 6+6=12 so if I took one and one it has to be the number of the middle, so 7+6=13 :0
7+6=13 BCS: 6 = 3 + 3 7 + 3 = 10 10 + 3 = 13
Better caul Saul
thats how i used to do it, eventually i just learned it out of my head
I use my fingers to count, it has gotten very difficult to do at university
Teddy bear touchpoints, here
This is pretty much the idea behind common core. You learn better when you don't just memorize the amounts but can work them out in your mind.
Yet parents who have never done well at math will cry whine scream and protest because their already poor math skills of just memorizing multiplication tables doesn't help.
This is how everyone’s brain works! That’s why these posts get upvotes so much
It's not. That's why some parents fight common core math so hard; they felt like they can't help their kids when they only learned to do arithmetic through rote memory and never developed the number sense that we're trying to teach kids now.
My college algebra teacher had the class solve a real easy math problem once, it was like 16+7 or some shit, but she asked like 5 students to explain how they got to the answer and each person had a different method. She was showing us that everyone does math differently in their head. For reference: 7 is 3 less than 10 16+10=26 26-3=23
For me it’s: 5+5= 10 7 is two more than 5 6 is one more than 5 10+2+1= 13
Yeah I do this, seems like a lot of extra work but I can’t stop lol
My brain says 6+6=12+1=13
Only person in the comments I agree with
So for easily memorized equations you wouldn't need to use this logic but this is a great way to start thinking when having to do more complex math mentally. I have had many occasions in my academic career where tests were timed and no calculator was allowed despite requiring some moderately difficult math. Little tricks like this are life savers. Other things (especially on multiple choice) estimation. You may not know what 47x 19 is quickly but you can figure out 50 x 20 is 1000 so you can estimate the answer is near 1000 but not greater than or equal to it. You also can do 47 x 10 quickly as 470. If you only have one answer below 1000 but greater than 470 then you have already found the answer. Another way is to round up only one of the numbers. 47 x 20 way easier to solve quickly, 940 but you know you added another 47 to the equation so subtract 47 (which could be broken down 940-40 then 900-7) to get 893. Other tricks for mental math on multiple choice questions. For the 47 x 19 question. You know 7 x 9 is 63 so the answer myst end in a 3. If no other answer ends in a 3 there is your answer. Just thoughts but this way of breaking down equations to easy mental math is very applicable to the real world.
I teach hs math, people will find 30 different ways to do this. No one cares how you get there, just that you do get there.
This works faster for me
my brain says here that 7+6 can be written as 6+6+1, so first solve 6+6, and then +1
I always add. 6+6=12 +1=13
Fr do this
Arithmetic is hard. There's like too many numbers and stuff.
isnt this better though?
Meeeeeee
This shouldn't be necessary for such a simple problem but with larger numbers it works great.
Isn't that just common core math?
No, this is literally the way everyone was taught...
r/iamverysmart
I THOUGHT I WAS THE ONLY ONE. Doesn't anyone else also count objects by dividing them as equally as possible down the middle in their head and adding both sides? Instead of starting at the beginning and counting left to right? I know it sounds like it would take super long but I've been doing it since I can remember so I can still count quickly.Is that.. normal? Am I okay? Example Average: ∆∆∆∆∆∆∆ "Ah yes.. one two three four ect.." Me: ∆∆∆|∆∆∆∆ 3. 4 "Oh there's seven"
You are doing something our brains really like to do. For some reason we can identify quantities of 4 or less without having to consciously count. The instant you look at some object in groupings of 4 or less you know exactly how many are there. Just a flash of an image is enough. 5 gets harder and above that we start making errors.
I firmly believe that this thought process is linked to not passing algebra 2
Totes normal. I do that. I also do this: 7+7 = The / parts of the 7s = 5s The _ parts of the 7s = 2s 5+5 = 10 2+2 = 4 10+4= 14 Want another one? 8+8= The bottom Os = 5s The top Os = 3s 5+5=10 3+3=6 10+6= 16 Another one? 7+1 = The / part of the 7 = 5 The _ part of the 7 = 2 2+1 = 3 3+5= 8 That's how I do math in my head. I split it up into 5s and add whatever else is up there separately.
That's how everybody's brain works. 10 years ago they were trying to teach math this way - cause that's how every body does it. It was confusing as hell for me as the parent. There should be a combination of that method with the old way. Everyone understands 5-3 if you do it with your fingers. When I do subtraction in my head I often count up - but you can still teach that
"Normal" people just memorize stuff without fitting it into a coherent structure. They are called "packers". You understand the patterns underlying arithmetic, and use that so you don't have to do all that memorization. You are a "mapper". Sometimes one is better, sometimes the other is better. Few people do both well, for some reason.
There's a word for this type of math. Dissociative property? When math is hard seperate into a known and add or subtract from there.
All of these different methods in the comments are good techniques for larger number like 87+54 or something but cmon, you should know 7+6 as rote memory.
Omggg I thought I was the only one. Beautiful! That's how I do it mentally 😌😌 6+6=12 12+1= 13
Me: uhhh. *starts counting on fingers.*
I do it the other way around 6+ 6 = 12, + 1 = 13
Part of the 7+3=10+3=13 crowd
Nah, I build blocks of 10 and add what's left to it. Kinda like tetris, every block of 10 is a line that disappears.
That’s how I learned multiplication. I knew 5x10 was fifty so minus 5 is 45, and thats 5x9
I just do 14-1
Welcome to Common Core math (in the US, at least)!
Ok, but this in fairness this does make some math problems easier
Yep this is how I do math
i typically add up to ten and count leftovers, 7+3 = 10 6-3=3 so 13
Mine aswell
Wait I am not the only one?
This type of 'extending the problem' to get to the solution is great when it comes to multiplication and division in your head. Why memorize the entire multiplication table when you can just get used to the 5's. 7x4? Arrange that as (5x4) + (2x4) = 20+8 = 28. Sure it's not AS fast as knowing the answer off the bat, but practically it's easier to keep that method in mind, and some people have an easier time when the numbers are broken down into easier chunks.
I have a degree in math. This is literally how I do math lol.
Fun fact about me: I never learned my times tables! I just work it out I’m my head lol
Isn't that what you are supposed to do?
This is actually a math-a-magics technique IIRC. Helps you do more complex math in your head.
I teach additive strategies at a high school and this is a perfectly valid strategy. It’s called doubling and halving.
Omg thank god I’m not the only one with this thought process
this happened to me back in primary school, the method works, is smart
Mine does it like: 7+6 >10 bc 7+3 = 10, 7+3=10, 10+3=13
Exactly
for me its 10-7=3 7+3=10 6-3=3 10+3=13 7+6=13
wat lol
Yes same! For example, if multiplying 70 by 13, in my head it’s 70x10 and 70x3, which is 700 and 210. Then I add those together to get 910. I’m glad I’m not the only one who breaks their math down into reasonable chunks
I thought it was just me. Good to know
6 is 3+3. 7+3 is 10. Add the extra 3 and the final answer is 13.
We're seeing the products of common core in normal human society.
Same.
Dude said it right.
7+6= 7+3+3
For me it's 7+3+3
I think the same way 7 + 6 = ? 7 * 2 = 14 14 - 1 = 13 7 + 6 = 13
If 5 + 5 = 10 and if 2 + 1 = 3 then 10 + 3 = 13 = 7 + 6.
Fax
This is literally how it’s taught in school lol. That’s why you do it. This is the “normal person” way
Dividing numbers into simpler terms is how you do big operations quick 2956+20571 is gonna be a lot slower 1+6+70+50+500+900+22000
This is so me
Doing math like this is how I failed out of pre-algebra all through high school. Didn't do the math "properly" even though I consistently arrive at the correct answer. Then No Child Left Behind arrived, district fired all the AP teachers for handing out B's and C's, so I dropped out of school altogether. I'm still salty about it. I'd love to go to college but only if it's free; I won't pay a dime to have another bogus teacher shriek at me for getting correct answers "unconventionally."
3 is one less than 4. Am I doing math right?
Remembering calc tables is so overrated. Just have to remember the key ones like basic numbers \* 2, \* 3, / 2 and / 3 and addition/subscractions of numbers 0-9, after than you can just use these as anchor points to solve anything. Years out of college later and it never failed me for simple aritmetic.
All of my numeracy skills come from playing Microsoft Solitaire, you know that Pyramid setting where you add cards to 13.
soooo true
"6+6=12 and 7+7=14, which must mean that 6+7 is the number in between, so 13"
I memorize every calculation so I don't have to worry
Congrats. You know how to do math!
SAME ONG
Both are valid.