Figure 4.4 Strategies for Dividing
Partial Quotients (modeled with open
array)
589 ÷ 7
40 + 40 + 4 r1
280 280 28
Halving and Halving
144 ÷ 12
72 ÷ 6
36 ÷ 3
12
Paper and Pencil
(Grandma’s Way)
8 4
7 5 8 9
–5 6
2 9
–2 8
1
Friendly Dividends
589
7
40 + 40 + 4
280 + 280 + 29
7 r1
84 r1
Figure 4.3 Strategies for Multiplying
Distributive Property (modeled with
open array)
15 × 18
10 + 8
10
5
100 + 80 + 50 + 40 = 270
Doubling and Halving
15 × 18
30 × 9 = 270
Partial Products (modeled with carets)
15 × 18
10 5 10 8
10 × 10 = 100
10 × 8 = 80
5 × 10 = 50
5 × 8 = 40
270
Paper and Pencil
(Place value)
4
15
× 18
120
150
270
+
100 80
50 40