Worked examples
Two examples
Example 1
−4 + 9 − 12 + 3 =
- Rewrite the subtraction: −4 + 9 + (−12) + 3.
- Add the positives: 9 + 3 = 12. Add the negatives: −4 + (−12) = −16.
- Combine: 12 + (−16). First subtract: 16 − 12 = 4. The sign of −16: negative.
Answer: −4
Example 2
6 − (−2) − 9 =
- Rewrite: 6 + 2 + (−9).
- Positives: 8. Negatives: −9.
- 8 + (−9): first subtract, 9 − 8 = 1; the sign of −9.
Answer: −1
Where this is taught: Signed Numbers, Part 9: three or more numbers
The drill
Ten problems
How many:
Type each answer, then press Check my answers at the bottom. For a minus sign, the hyphen key (-) is fine.Write each answer on the line. The answer key, with the reasoning, is on the last page.