Breaking apart addends as a way to solve an addition problem means to reorganize the numbers in a way that makes the numbers easier to calculate. This multistep technique often involves rearranging the addends -- the numbers being added together -- into groups of tens and ones, and then adding the tens and ones individually before adding them together to produce the final sum.

Restructuring for Tens and Ones

Step 1

Write the addition problem 27 + 13 = ___ on the paper.

Step 2

Break 27 into 20 + 7, and 13 into 10 + 3.

Step 3

Add 20 + 10 to get 30. Then, add 7 + 3 to get 10.

Step 4

Add 30 + 10 to obtain the total sum of 40: 27 + 13 = 40.

Warnings

  • Remember that any number value you take away from one addend must be added to another within the problem, or else your sum will be incorrect.

Tips

  • Instead of restructuring simply for tens and ones, you can also restructure to create groups of tens -- numbers that end in zero. For example, in the problem 27 + 13 = ___, you could combine 27 and the 3 from 13 to get 30 + 10, which produces the same sum of 40. You can also restructure to create groups of fives along with tens: 22 + 13 = 35 becomes 20 + 10 + 5 = 35. Whichever organization you choose for a problem, remember that you are reorganizing the numbers to make the problem easier.