Grade 8 · Number · Integer Multiplication and Division
Reason with Integer Products
The magnitude of an integer product uses whole-number facts. Its sign follows from direction, repeated change, patterns, and the inverse relationship between multiplication and division.
The big idea
The sign carries the direction
Four daily drops of 3 degrees total −12, so 4 × (−3) = −12. Continuing a product pattern shows that multiplying two negatives produces a positive.
Work it through
Evaluate (−6)(−4) and explain
- 1. Use the magnitude fact 6 × 4 = 24.
- 2. A negative times a positive is negative: (−6)(4) = −24.
- 3. As the second factor decreases from 4 toward −4, products increase by 6 each step.
- 4. The pattern reaches +24, so (−6)(−4) = 24.