Subtracting Numbers Within 100 With Regrouping
Page 5 of 6

 
Now, we'll finish it off quick! 

Subtract the ones...  Then, subtract the tens...

Work for 75-28...  Subtracting the ones Work for 75-28...  Subtracting the tens

So, 75-28=47

Practice some by writing your problems out this way.  Then, you'll really know what's going on.  Once you get really good at it, this is the short-hand way of showing your work (and the way most people do it):

1) Make a scratch through the 7 since you're going to lower it by 1

Work for 75-28

2) Put the 6 above the 7 (the 6 is what's left when you take 1 ten chunk out) :

Work for 75-28

3) Put a 1 by the 5, making it 15:

Work for 75-28

4) Finish it off!

Work for 75-28=47

I'm going to use this faster way of showing my work in the next lesson, so you can get used to it!

I've got some practice problems with the faster way on the next page!

 

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