To Turn or Not to Turn

Many students try turning division problems around when this is inappropriate. For example, 4 ÷ 20 is seen as impossible, so students turn it around to 20 ÷ 4 and get 5.

Using Materials

Problem: “Make up word problems for each of these divisions: 4 ÷ 2 and 2 ÷ 4, and solve them. Use fraction pieces to help you.”

(Answer: Jane has 4 chocolates to share between 2 people altogether. So 4 ÷ 2 = 2.  And Jane has 2 chocolates to share among 4 people altogether. So 2 ÷ 4 = 1/2.)

Examples: Repeat for: 6 ÷ 2, 2 ÷ 6 6 ÷ 3, 3 ÷ 6 12 ÷ 2, 2 ÷ 12 ...

Using Number Properties

Examples: Examine the pattern in the pairs of answers above then work out these: 
15 ÷ 3, 3 ÷ 15 100 ÷ 10, 10 ÷ 100 60 ÷ 3, 3 ÷ 60

Understanding Number Properties:

If the answer to a ÷ b is c, what is the answer to b ÷ a? (Answer: 1/c .)