Arithmetic Grade Three

Lesson Twenty-six: Step By Step Regrouping

Regrouping can be difficult at first since most students like to just fall back on counting up the sum. Counting up the sum works, but it can be very slow compared to carrying. Here's another example for you to study. 

   37
  +43
  ----
When we add up the digits in the ones column we get 10 and so we write the one above the tens column and the 0 in the ones column in the answer space: 

   1
   37
  +43
  ----
    0
Next we add up all the numbers in the tens column: 

   1
   37
  +43
  ----
   80
Here's another example: 

    47
   +49
   ----
Problem without answer

    1
    47
   +49
   ----
     6
Adding the 7 and 9 in the ones column we get 16. We take the 6 from 16 and place it in the ones column of the answer and we carry the 1 above the tens column above the addends.

    1
    47
   +49
   ----
    96
We add up the 1, 4, and 4 in the tens column.

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