Doubling and Halving Strategy
25 x 30 = 50 x ____
15
Draw a rectangle.
Width = 4cm
Area = 32 cm squared
Length = ?
8cm
Use a ratio table to solve: 5 x 12
60
13 divided by 2
6 R1 or 6 and a half
Length = 16 ft
Area = 32 ft
Width = ____
2 ft
T or F
10 x 2 = 20 x 4
False, it would need to be
10 x 2 = 20 x 1
or
10 x 2 = 5 x 4
Use the are model to multiply:
13 x 27
351
Use a ratio table to solve 17 x 35
595
74 divided by 8
9R2, 9 2/8, or 9 1/4
Area of a path = 8,024 ft
One dimension is 8ft.
What is the length of the other dimension?
1,003 ft
Solve using the doubling and halving strategy.
25 x 32
25 x 32
50 x 16
100 x 8 = 800, so 25 x 32 is also 800.
Use the area model to multiply:
35 x 72
2,520
Use a ratio table to solve
145 divided by 5
29
4th grade is setting up a playground for field day. There are 360 balloons to split among 9 tables. How many balloons at each table?
40
The total perimeter of a rectangle is 846cm.
One dimension is 134 cm.
What is the length of the other dimension?
289cm
Solve using the doubling and halving strategy.
13 x 24
13 x 24
26 x 12
52 x 6
104 x 3 = 312, so 13 x 24 is also 312.
Use the area model to multiply:
123 x 45
5,535
Use a ratio table to solve:
182 divided by 13
14
Eight friends are going skiing. They are paying a group rate of $264. How much does each friend need to pay?
$33