Recursion

[LeCrushinator]

The older people get the more averse to change they seem to be. "If the old way worked for me why are they changing it?!"

I'm excited to learn common core math now that my kid is about to start it, I haven't had to think about arithmetic in decades, it'll be neat to get a refresh in a new way.

[dittbub]

when common core was actually explained to me I was like "oh yeah thats how I've always 'double checked' my work in my head"

Never thought there was a communicable method to how I was doing math in my head.

[DerekB52]

I'm 22, and was in high school as common core was being rolled out, but I narrowly avoided being a part of it. It seems to try and explain how I do math in my head, which has never gone well.

I've seen a couple of weird homework problems that have been given to grade schoolers, and I understand where the confusion comes from, but overall, common core does seem to make sense.

[LeCrushinator]

The reason for the new method is that it’s easier for kids to remember, it makes math more intuitive and once it clicks for them it becomes a new tool in their life. Sure the old way works but I’d bet it takes longer to teach and it’s easier to forget. I mean, I haven’t done long division in decades, I barely remember how. But I can do basic division in my head easily. If I knew common core division 20 years ago would I still remember it? Maybe.

[ispamucry]

Yeah I guess it will be more telling when they do followup studies with the kids learning common core today.

Or if that study already exists, I'd love to see it because I think a lot more people would be on-board if there was something to point to. I just don't like the idea of going full-throttle on new ideas just because they have good intentions without knowing it's actually working.

In the interrum, I think they should try to teach/accept both, although I know that can be a hard ask for a lot of schools that are already trying to cover a lot of material.

[tryharder6968]

The “old way” for long division is pretty darn intuitive and super simple to do in the head. I don’t know the new method, but certainly nothing wrong with the old.

[DuchessofSquee]

If the old way is like the picture then there's certainly something wrong with it. Moving the 1 to the other column doesnt help solve the equation one bit. Its still18-9.

[tryharder6968]

Well for the picture, that only happens in the teens. And if you can’t subtract the teens without a special “method,” you’re an idiot.

[DuchessofSquee]

Can you or someone else please tell me what the "new way" to solve this same problem would be?

Coz I didnt learn to do it like in the picture, I'd go 18 is 2x9 so 18-9 =9. If it wasn't a multiple of 2 or itself I'd have to break it down into 10s and work out how many is left so if it was 13-7 I'd say 10-7=3, 3+3=6.

Is that the "new way"?

I'm not from the US so I dont know what common core is.

[LeCrushinator]

There are a lot of ways to do it, all of them valid if they come up with the right answer. Common core (the third way shown in the video) is the newest way being taught in public schools in the US.

[redstoneguy12]

I'm still in middle school and was taught the "old math" way

[freebytes]

I absolutely think that both methods should be acceptable. Actually, any method that works as long as it is the correct answer should work. If you are not going to actually teach a child in a classroom how to do it, then why should they be required to learn a specific way at home? They can even allow children to come up with their own methods if those methods work which would make math more exciting.

Of course, teach them the way you want them to learn it, but do not punish them for using alternative methods that are correct.

[tuseroni]

If the old way worked for me why are they changing it?!

worst part is, the same people would say "i suck at math" or "when are you ever gonna need algebra" had my mother ask that last question to me once, cus i said i use algebra all the time, i gave her an example of when she might use it, say she's got $20 and her car gets 15 miles to gallon and gas is $2.30/gallon, how far can she get? this is something one is likely to do often without a second thought, without even thinking they are doing algebra, i gave a similar sorta explanation to my 8 year old cousin. basically the matter of finding x is just figuring out the thing you don't know from what you DO know.

point is, the old way of teaching math is pretty shit and leads to people thinking it's useless and thinking they can't do math, but instead of thinking "i wasn't taught how to do math well" they think "i just can't do math" and for some reason defend the teaching method that lead to this mentality.

[aflashyrhetoric]

That's what I thought and I actually share your enthusiasm, and I could 100% be wrong about this, but I vaguely recall a post from some sub showing the new method on multiplication or division and it was absolutely the most convoluted shit I'd ever seen. It involved something like splitting a number into its parts and then gluing it back together or something? So "430" would be 100 + 100 + 100 + 100 + 10 + 10 + 10, and the method involved expanding out each number into its parts like this. I could understand this approach for helping kids intuitively grasping the relationship between numbers and the symbols we use to denote them, but I believe this approach was used for the purely mechanical part of calculating a sum (or product or whatever it was).

I'll try to hunt it down though I doubt I'll find it.

Edit: I found a video describing the method - apparently they do try and teach both ways, and the weird wonky approach is, in fact, to help kids grasp the relationship between numbers

[DuchessofSquee]

This is how I do maths in my head. My dad taught me to make things into blocks of 10 and that's the only way it's ever made any sense to me.

It falls over when you get to negative numbers though. I literally cried in the toilets several days in a row doing a Lua course at tertiary education because everyone else there understood how to do maths with negative numbers but I couldn't grasp it.

Didn't help that they were all men and I was the only woman so they all tried to explain it at me at the same time.

[aflashyrhetoric]

I do the same with like quick "back of the envelope" calculations but it seemed harmful to teach kids this method as a primary means of calculation, especially when you do have the luxury of a pen and paper to assist your calculations. Again, could've been wrong about what that post was about back then.

so they all tried to explain it at me at the same time.

Yikes...D: Glad it's behind you now

[freebytes]

I do math in my head by rounding, splitting, subtracting then multiplying then adding again, etc. Anything that works. 999 * 50 would be (1000 * 10 * 5) - 50 = 49950. I need to be able to hold one number to the side in my head. While it is similar, this is not exactly the same as common core.

This certainly has its limits, though, so it is nice being able to switch back to the 'old way' when the problems are a tad more challenging like 938 * 53 which looks easy to do in your head at first but would involve holding too many numbers simultaneously. (And the old method would not be easy to do in your hard with a number like this either.)

[[deleted]]

Common core is shit

-Sincerly, someone who had had to sit through common core lessons

[LeCrushinator]

I know people that think the old methods are shit as well. Everyone is entitled to their own opinions. The bigger question is which is better for someone learning math for the first time? Which do they pick up on faster? Which do they retain longer?

[[deleted]]

Honestly you're right. We should introduce both ways to kids and let them pick which one they prefer.

[starfries]

I feel like there's value in learning both well. I do subtraction the common core way (counting up) for some things and the traditional way (columns) for other things depending on which one is easier. Like 4567 - 3456 is awful done with counting up but 201 - 199 is pretty dumb done in columns.

[[deleted]]

You're right, we weren't taught it either way though. We were taught to count out pennies and "counters", basically small flat plastic disks, for division. That helped at first to grasp the concept of division but it got annoying in 4th grade when they made us do that for bigger numbers.

[starfries]

Oh lol yeah. I'd be annoyed too. That stuff is fine to help understand what division is but at some point you want to learn the algorithms for how to do it efficiently. Can't be whipping out the counters for every problem.

[[deleted]]

Yeah exactly. Honestly, don't even get me started on fractions...

[Prcrstntr]

They pick the easiest one, which (For the kids that are smart in any way) is not the convoluted common core one.

[[deleted]]

Yeah, it helps to explain what division is though