Addition and Subtraction
2-4Subtracting Real Numbers
Overview
To subtract a number, add its opposite: a − b = a + (−b).
Key ideas
- Change subtraction to addition of the opposite.
- Then apply the rules for addition.
- Two minus signs together become a plus.
Worked examples
Example 1
Problem. 5 − (−3)
Solution. 5 + 3 = 8
Example 2
Problem. −4 − 6
Solution. −4 + (−6) = −10
Practice
Try each one. Click Show answer when ready.
- 1.
−7 − (−2)
- 2.
3 − 11
- 3.
−9 − (−14)
Challenge problems
A little tougher — great for test prep. Click Show answer when ready.
- 1.
Simplify 5 − (−3) − 8 + (−2).
- 2.
Simplify −4 − (−7) − 3 + (−1).