Multiplication
2-6Rules for Multiplication
Overview
Same signs → positive product. Different signs → negative product. Zero times anything is zero.
Key ideas
- (+)(+) = +, (−)(−) = +
- (+)(−) = −, (−)(+) = −
- Count negative factors: even → +, odd → −.
Worked examples
Example 1
Problem. (−4)(−6)
Solution. 24
Example 2
Problem. (−3)(5)(−2)
Solution. Two negatives → +; 3·5·2 = 30.
Practice
Try each one. Click Show answer when ready.
- 1.
(−7)(3)
- 2.
(−2)(−9)
- 3.
(−1)(−1)(−1)(−1)
Challenge problems
A little tougher — great for test prep. Click Show answer when ready.
- 1.
Simplify (−2)(−3)(−1)(4).
- 2.
If a = −2 and b = 3, evaluate ab² − a²b.