Gifted Issues Discussion homepage Forums General Discussion Math Trick Question

Oh, only 6! I thought he was older for some reason. 6 is very appropriate for still to be calculating these facts IMO, and I think it's great to be able to manipulate numbers in ways like this.

I was amazed. But I didn't know if I was amazed because I couldn't figure it out at 47 (my age) or if it was unusual for his age. LoL

Hopefully, he loves math as he grows. I always hated it.

LoL... I'm 33 and still sometimes have to count out in my head. And I nearly always use factors of 5 or 10 to solve math problems. I just can't hold numbers in my head well at all.

I think it's quite possible that he discovered it himself. My DD6 does subtraction this way too, and she has no other sources to learn it from. This is however similar to the "getting to the next 10 or 100" method in addition, which she might have learned from her teacher.

This is similar to how I've always done mental addition or subtraction, and "discovered" the method independently, like your DS. My algorithm is a little different, but it's the same principle.

Personally, I find it highly advantageous to have a simple algorithm that works in any and all cases, rather than using the algorithm in some cases, and memorizing "math facts" (don't get me started on how I loathe that term) for others. It greatly enhances speed and accuracy.

Dude +1, for all of that. i do a version of this, too.

AND i think working out their own methods really reinforces a kid's comfort with math.

DD5 worked out a trick for multiplication recently and while i expect she'll be able to remember the entire table soon, she's REALLY enjoying her trick. working out your own way seems like a one-way ticket to confidence, so that works for me.

Yea, there's a trap there. I probably get too eager to share tricks with my DS to the detriment of his own discovery/ownership/pride. Though he won't take things at face value. Last week I told him one shortcut, and he tried it, then tried the regular way and did that for a few more problems before deciding my input was valid.