Addition using groups of 10 and 100 (Full video)

Khan Academy

Supporting grades: 3

Description: Sal rewrites addition problems to make them easier to solve. So, let's do some practice problems on Khan Academy exercises that make us rewrite an addition problem so that we can get them to rounder numbers. So, let's see here, I have 63 plus 427, and that seems kind of hairy, you know, it feels like I wanna write those things down, but maybe I could take away from one of them, and give it to the other one so that they both become round numbers, and it's clear that 63, if I were to give three away I would get to 60, and if I were to give those three to 427, it would get to 430, and 60 plus 430 is a much simpler problem. So, the 60 plus what, this is gonna to be the same thing as 63, cause we have 427 in both places, so 63 is 60 plus three.

You must log inorsign upif you want to:*

*Teacher Advisor is 100% free.