Activity 01
Pattern Investigation: Building the Integer Multiplication Table
Small groups fill in a multiplication table that includes rows and columns for -3 through 3. They first complete the positive portion using known facts, then use the decreasing pattern in each row to extend into negatives. Groups record what they notice about the signs and share a rule they derived from the pattern.
Why does multiplying two negative numbers result in a positive product?
Facilitation TipDuring Pattern Investigation, have students work in pairs to complete the table row by row, discussing each new product before moving forward to reinforce the pattern.
What to look forProvide students with three problems: 1) 5 x (-3), 2) (-7) x (-4), 3) (-2) x 3 x (-5). Ask them to calculate the product for each and write one sentence explaining the sign rule used for problem #2.