**there**. How skip counting relates to multiplying is just

**there**. That reversibility of addition to subtraction and multiplication to division is

**j**

**ust there.**

But place values are HARD. Wrapping your mind around there being zeroes in the

*middle*of numbers that aren't, say, 10, or 100, is a serious does not compute. Until it is the only thing that makes sense, and then how do you explain why it was hard?

(Deleted comment)jeliza(And what really sucks is if you didn't get a really firm handle on something in, say, 2nd grade, and you get to where it is relevant in 3rd grade problems that are too big to do in your head, the frustration level is immense.)

I am so glad I am not a teacher. We really don't pay them well enough for the number of skills they have to have, and what they put up with.

dianthusjelizaI see a lot of kids (I volunteer at math) that can do problems, even much harder problems, intuitively, but can't explain how they are doing them, which eventually fucks you up whenever you hit the point you have to do not-in-the-head math like multiplying three digit numbers, or when you have to write it out.

joxnfour thousand, twenty, six, that is:

4000

+ 20

+ 6

------- and now, writing from right to left, and tracking across the 4000 and then down to the result digit

4..0..2..6

jelizadianthusindigodoveExpanded form can help, ex: 402 = 400 + 0 + 2, or the kind of problem above (4026) on graph paper. Actually, I made them learn regrouping for both addition & subtraction on large-square graph paper, because it was easier to keep their columns straight that way.

But honestly, math was always hard for me, so I like to think I was good at explaining it. Explaining how to write or read well was much harder for me, because those things came easily to me.

Good luck and bravo for being a concerned parent who wants to help her kids! <3

jelizaApparently place values are on the 2nd grade Common Core tests/curriculum, which seems odd to me, but a lot of what is on those tests and when doesn't make sense to me.

I think the fact that English is written left to right doesn't help, because they want to write their

numbersleft to right, which just doesn't work, especially once regrouping is involved.eubGeneralizing like that may be a weird way to attack the problem, I guess, but it does also make it more concrete, and dispels any mystery around the powers of ten. There's a bit of a puzzle for the teacher when the student asks "what stops us from making it as 27 $1s?", but that's a good question to have. :)

jeliza