Activity 01
Small Groups: Doubling Arrays
Provide counters for groups to build rectangular arrays for 4 times facts, like 4 x 5 as two rows of five. Instruct them to double by mirroring the array exactly, forming 8 x 5, and record the fact. Discuss why results are even and share findings.
Analyze how we can use the 4 times table to quickly calculate the 8 times table.
Facilitation TipDuring Doubling Arrays, circulate to ask each group to verbalize how doubling the 4x array creates the 8x array before they build it.
What to look forPresent students with a series of multiplication problems involving 3, 4, and 8 (e.g., 3 x 7, 4 x 5, 8 x 2). Ask them to write the answer and then circle the problems where they used the doubling relationship between the 4 and 8 times tables to find the answer.