Regrouping

When I was in school, I learned the old school, "borrowing" way. I did it, and I got my answers correct, but I had no idea why I was crossing out the tens and changing the ones. It was totally mindless for me.
While it was nice that I got my answers right, it is more important to deeply understand place value.
That is part of the reason we teach all sorts of methods before we go into "borrowing."
Also, it is no longer called "borrowing." It is now called, REGROUPING.

I put my regrouping worksheet on teacherspayteachers for free!

Here is a video of me doing the worksheets.

The way we are told to teach regrouping is by first looking at expanded form.
Expanded form means that you look at the value of every digit in a number and adding them together.

For example 623 becomes 600 + 20 + 3

So how does that translate to borrowing regrouping?
If I am taking 623- 351 that becomes
  600 + 20 + 3         I can take 1 away from 2. But I cannot take 50 away from 20. I need to borrow   
-300 + 50 +1          regroup. So I change the problem into
___________

500+120+3

-300+50+1     

______________

200+70+2

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