Multiplication and Division Concepts
Warm-up
I have 4 groups of 5 linking cubes. How many cubes total? Count by 5s: 5, 10, 15, 20. Write the addition: 5+5+5+5 = 20. Write the multiplication: 4 x 5 = 20. All three say the same thing. Now rearrange into an array: 4 rows of 5. Does it still equal 20?
Explore
Fish drying scenario: a community is preparing for winter. Each drying rack holds 6 fish. How many fish on 7 racks? Model with cubes. Write the multiplication. Now reverse: 42 fish, 6 per rack. How many racks? Write the division. Discuss: how are these two problems related?
Consolidate
Practice
Students solve 4 multiplication and 4 division problems in context (equal groups, array, sharing, grouping), showing concrete or pictorial models for each. Exit ticket: write a division story for 36 / 6 = 6 using the fish-drying context.
Exit ticket
Students solve 4 multiplication and 4 division problems in context (equal groups, array, sharing, grouping), showing concrete or pictorial models for each. Exit ticket: write a division story for 36 / 6 = 6 using the fish-drying context.
Multiplication: a canoe carries 8 people. 5 canoes travel together. How many people? (5 x 8 = 40.) Division (partitive): 40 berries shared equally among 8 people. How many each? (40 / 8 = 5.) Division (quotitive): 40 berries, packed 8 per basket. How many baskets? (40 / 8 = 5.)
Draw a 6x4 grid (6 rows, 4 columns): 24 squares. Draw a 4x6 grid (4 rows, 6 columns): 24 squares. Both arrays contain the same number of squares. Rotating a 6x4 array 90 degrees produces a 4x6 array: same total, different orientation.