Model Integer Subtraction

Subtraction as Addition

Work Time

Subtraction as Addition

Subtraction is the inverse of addition. So, subtraction problems can be written adding the opposite of the number. Subtracting a positive 2 is the same as adding a negative 2.

For example: 8 − (−2) = 8 + 2 = 10

Write these subtraction problems as addition problems:

  • 7 − 4 = 7 + ____
  • 3 − 10 = 3 + ____
  • −5 − (−9) = −5 + ____
  • 1 − (−5) = 1 + ____

Hint:

In the first problem, when you subtract 4 on the number line, you go 4 units to the left. What addition does this represent?