subtraction

Arithmetic Grade Three

Look at this subtraction problem:


     32
    -18 
   -----

To solve this problem, we regroup like this:


    tens   |   ones
   --------|---------
       2   |    12
    -  1   |     8
    -----------------
       1   |     4

Here's another easy example:


     44
    -27 
   -----

Here's the same problem after regrouping:


     3  |  14
   - 2  |   7 
   ------------
     1  |   7