Worked examples
Two examples
Example 1
−3 + (−5) =
- Both numbers are negative: same signs, Rule 1.
- Add the absolute values: 3 + 5 = 8.
- Keep the sign they share: negative.
Answer: −8
Example 2
−12 + (−9) =
- Same signs, Rule 1.
- 12 + 9 = 21. Keep the negative sign.
Answer: −21
Where this is taught: Signed Numbers, Part 5: Rule 1
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.