Hungry 9

You can't take three from two,
Two is less than three,
So you look at the four in the tens place.
Now that's really four tens,
So you make it three tens,
Regroup, and you change a ten to ten ones,
And you add them to the two and get twelve,
And you take away three, that's nine.
Is that clear?

Tom Lehrer, "New Math"

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.

Mental arithmetic is all little tricks and shortcuts. If the answer is right then there's no wrong way to do it, and maths is one of the few places where answers are right or wrong with no damn maybes!

What does adhd have to do with anything?

Has nothing to do with ADHD.

I would have done 10+6, but that's effectively the same thing as the OP.

Aside from literally counting, what other way is there to arrive at 16? You either memorize it, batch the numbers into something else you have memorized, or you count.

Am I missing some obvious 'natural' way?

Why is everything ADHD?

The "ADHD way" is literally what they are teaching in school.

Why are these posts always shitting on teachers? I don't know what teachers you're seeing, but I've never seen any teacher of any subject / age-group ever discourage anyone for thinking about something a different way. Quite the contrary, different ways of approaching problems are always encouraged.

You're old school, like me. You're literally describing the "new math" that boomers hate. Teachers are finally teaching kids to do it the way we've always done it in our head.

"8 + 7 is awkward, but if you take two from seven and give it to eight, now you have 10 + 5 and that's easy mental math."

If your teacher gets mad about breaking an addition problem into easier problems, then that teacher should be fired. Phony tale.

No no no 10+7 = 17 and 9 is always one less so 16

Let's make that 9 a 10 because it's good enough, it's smart enough, and goshdarnit people like it. Also, I don't wanna add with a 9. So 10 + 7 would be 17, but we added 1 to the 9 to make it 10 so now we take 1 away, 17 - 1 = 16.

ezpz

Whatever number is closest to 10 steals enough to make itself 10. Same goes for hundreds, thousands, whatever. Get your round numbers first, add in the others later. All numbers must become 10. In a pinch, a number may become a 5, but if so, it's really just become a half-10, and it should feel bad about itself that isn't a full 10 yet.

10 is just easier for me to work with so...

9+1=10 10+7=17 17-1=16

The second method is very chemistry-like. I do that too naturally

It took me 3 years to pass HS algebra because the coaches/part-time math teachers didn't like the way I solved problems. I got the right answers. But the way I got them was wrong apparently.

No no no. Adding nine is just subtracting one, but adding to the front digit. 9 + 7 is actually 7 - 1=6, then add that 1 to the front. 16. Let's not make more complicated than it needs to be.

this is a false story. everybody knows 7 ate 9

I realized something. I relate so much to ADHD memes not because i have it but because they simply do a lot of things that they think only people with ADHD do. In my school they encouraged you to come up with techniques like this. Often 9 is hungry in different ways. Another exmple is multiplication. 5099 is 50100-50 which is much easier to calculate.

Yo but hear me out. Because 7 ate(8) 9, 7 + 9 = 7

8+8 and 8X2 are literally the exact same thing, why did they feel the need to make that an extra step?

9 is 3+3+3, 7+3 is 10, 3+3 is 6, 6+10 is 16. I'm also a fucking heathen.

This picture just describes the 'new math' that everyone bemoans.

7+9=7-(10-9)+10

I explained to a teacher one time this as my method, the get to ten version, and she looked confused as hell like why would anyone do that. She was cool with it though, gave me a whatever works for you kind of response.

This kind of feels like how I constantly get the "which word/shape/number (etc.) in this series is incorrect" questions on tests wrong. I severely overthink it. "Well, these four all have chloroplasts and this other one gains energy from photosynthesis via a symbiotic relationship with another organism, so it must be that one."

*Gets test back*

"Oh, it was the one that didn't live in a rain forest."

I think that third one down is actually how they’re teaching it at my kids’ schools now. It’s called “making a 10” I think, basically that same idea, add up to 10 first, then do the rest.

Okay this is nice and all but how do people do 3974* 438 mentally, without paper? And bigger and some outright freaks seem to do it in an instant

9+7=10+7-1=16

I like the way the second ADHD method is also a flip on the "seven ate nine" dad joke

Me, bad at math: yeah they taught us that as a way to do in grade school.

Intellectuals, apparently: easy math

You, with ADHD: I like my easy math with an extra step or two

Me, literally clinically insane: preeeeeetty sure I find a way to solve that using the factorializing of transfinites and [TREE]3 somehow, maybe not

Googologers: HOLD MY UN/COUNTABLE INFINITIES, BITCH

_

see thats why i have "undiagnosed" adhd is this truly an adhd thing?