this post was submitted on 18 Oct 2024
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[–] [email protected] 38 points 6 hours ago (3 children)

Common core made an effort to teach kids to think about numbers this way and people flipped the fuck out because that wasn't how they were taught. Still mad about that.

[–] [email protected] 20 points 5 hours ago* (last edited 5 hours ago) (1 children)

The problem with common core math was not that they taught these techniques. It's that they taught exclusively these techniques. These techniques are born from the meta manipulation of the numbers which comes when you have an understanding of the logic of arithmetic and see the patterns and how they can be manipulated. You need to understand why you can you "borrow" 1 from the 7 or the 9 to the other number and get the same answer, for example. It makes arithmetic easier for those who do it, yes, but only because we understand why you are doing it that way.

When you just teach the meta manipulation, the technique, without the reason, you are teaching a process that has no foundation. The smarter kids may learn to understand the foundational logic from that, but many will only memorize the rules they are taught without that understanding of why and then struggle to build more knowledge without that foundation later.

Math is a subject where each successive lesson is built on the previous lessons. Without being solid on your understanding, it is a house of cards waiting to fall.

[–] [email protected] 8 points 3 hours ago

To add to this, people come up with math tricks all the time but you then have to check it against the manual method, and often multiple times with different numbers, before you can connect the manual process to the trick for later use.

In my opinion I don't think you can teach just the trick side of it, if thats what common core is.

[–] [email protected] 5 points 5 hours ago* (last edited 5 hours ago) (1 children)

There's ~~people~~aliens who would add 9+7 instead of 10+6 or 8+8 in their heads?

[–] [email protected] 9 points 4 hours ago (1 children)

I do, because 9 plus anything is just a 1 in front of the other digit minus 1.

Weirdly enough, I just thought about using the methods here for the first time in my life earlier today. Weird.

[–] [email protected] 6 points 4 hours ago (2 children)

9 plus anything is just a 1 in front of the other digit minus 1

This is also how it works in my head, but isn't it the same as the other guy was saying, 10+6?

[–] [email protected] 3 points 2 hours ago

The difference would just be how you think of the process. I sometimes shuffle around the numbers to make math easier, but the shortcut for adding 9s just feels different. Instead of 9+7 = 10 + 6, it's more like 9+7 = 17-1. It feels less like solving it with math and more like using a cool trick, since you didn't really use addition to solve the addition problem.

[–] [email protected] 1 points 3 hours ago

Sort of, same numbers different logic. Its like mixing up the order of operations. You could learn both tricks but it seems redundant if they do the same thing. Like having two of the same hammer.