Column Addition: Carrying and Regrouping
Sometimes, you will see an equation that you can't solve just by using simple addition. Here's an example:
White Box White Box
Right To Left. We first see the 5, which is above the 7. 5 + 7 = 12. We put the 2 (from the 12) below the 7 and the 1 (from the 12) above the next column to the left.
Our equation is now:
White Box
White Box White Box
Again we go from Right To Left and see the 1 above the 3. 1 + 3 = 4 and 4 + 2 = 6. Our equation is now:
White Box White Box
So, the answer is 62.
Here's another example:
White Box White Box White Box White Box
Right To Left. We first see the 5, which is above the 9. 5 + 9 = 14. We put the 4 (from the 14) below the 9 and the 1 (from the 14) above the next column to the left.
Our equation is now:
White Box White Box White Box White Box
Again we go from Right To Left and see the 1 above the 4. 1 + 4 = 5 and 5 + 2 = 7. Our equation is now:
White Box White Box White Box White Box
Once again we go from left to right. 8 + 3 = 11. Because there are no more columns, we just write the 11 below the 3:
White Box White Box White Box White Box
So, the answer is 1174.
The process of putting a 1 above the equation when needed is called carrying or regrouping.
Continue to Next Page