Mulplication and Division

1. Multiplication and Division Strategies

3. Big Ideas Multiplication Division Symbols Language Special features Definitions

5. Time to Think!!! How might your students work these out?

6. Multiplication and Division Strategies for CA - EA Problem: A class of 28 students are going on a school trip. They are travelling by car. Each car can take 4 passengers. How many cars will be needed for the trip? How would you solve it if you were Counting All? What if you were an Advanced Counter? What about if you were Early Additive?

7. Where are these strategies on the Number Framework? 4 x  = 28 I got 28 counters and put them into groups of four. I found that we needed 7 cars. I counted using my fingers in groups of 4 and got to 7 fingers for 7 cars. I know 4 +4+4+4+4+4+4=28. 4 + 4 = 8 and 8 + 8 + 8 is 24 and + 4 is 28. So that’s 7 groups. I know that 4 x 10 = 40 so 4 x 9 = 36 and 4 x 8 = 32 and 4 x 7 = 28. I can skip count in 4’s so I went 4, 8, 12, 16, 20, 24, 28

9. Where are these strategies on the Number Framework? 18 x 4 =  18 x 4 is the same as 10 x 4 = 40 and 8 x 4 = 32 so 40 + 32 = 72. Triple 4 is 12 and a third of 18 is 6 so 12 x 6 = 72 Can you name each strategy? Double 4 is 8 and half of 18 is 9, So 8 x 9 = 72. 20 x 4 = 80. But that’s two plants too many in each row so takeaway 4 x 2 which is 8, so 80 – 8 = 72.

11. Where are these strategies on the Number Framework? 72 ÷ 6 =  Half of 72 is 36 and half of 6 is 3 so 36 ÷ 3 is 12. Can you name each strategy? 12 x 6 is 72 therefore 72 ÷ 6 = 12 Well 60 + 12 = 72. I know 60 is a multiple of 6 and so is 12 so 10 + 2 = 12 A third of 72 is 24 and a third of 6 is 2. 24 ÷ 2 = 12.

13. Where are these strategies on the Number Framework? What visual supports could you use to support these strategies? 24 ÷ ¾ =  so I know that ¾ x  = 24? If 24 is ¾ then ¼ is 8. So 8 x 4 = 32 pieces. 24 ÷ 0.75 =  24 ÷ 0.75 is the same as 48 ÷ 1.5 which is the same as 96 ÷ 3 =32. I know that 0.75m is the same as ¾m so now I can use this to… 0.75 is 1 piece 1.5 is 2 pieces 3 is 4 pieces So 3 x 8 = 24, then 8 x 4 = 32 pieces. +20

15. Activity Sharing