Bell WorkWrite the equivalent rate.

ANSWER $.20

ANSWER 4 c

1.1 hours

$ 12=

1 minute$ ?

2. 2 pints

1 person =? cups

1 person

Hint: 1 pint = 2 cups

ANSWER 1050 mi

ANSWER 40 cal

3.1 day

150 miles=

1 week ? miles

4. 320 calories1 cup

=? calories

1 fluid ounce

Hint: 1 cup = 8 fluid ounces

Scale

Drawings

ReviewSolve the proportion. Then check your solution.

b1.8

=49.6

14.4

14.4b = 1.8(49.6)

14.4b = 89.28

=b 6.2

Cross products property

Multiply.

Divide each side by 14.4.14.414.4

89.2889.28

=b

A man rides his bike at a constant speed for 2 hours and travels 30 miles. If he were to continue riding at the same constant speed, how many miles would he travel in 5 hours?

ANSWER 75 mi

ANSWER 225 min

A teacher can grade 4 tests in 25 minutes. At this rate, how long will it take her to grade 36 tests?

Review

Use the cross products property to solve the proportion.

If three bundles of shingles cover 75 square feet of a roof, how many bundles will it take to cover a roof that is 1800 square feet?

ANSWER 72 bundles

Scale DrawingA scale drawing

represents something that is too large or too small to be drawn at its actual size.

Maps and blueprints are examples of scale drawings.

ScaleIn math, scale

shows the relationship between two things as well.

With maps, it is usually between a distance measured on the map and the actual distance on the ground.

A scale drawing is a diagram of an object in which the dimensions are in proportion to the actual dimension of the object.The scale on a scale drawing tells how the drawing’s dimensions and the actual dimensions are related. The scale “1 in. : 12 ft.” means that for every 1 inch you have 12 feet.

SOLUTION

Using the Scale of a MapOn the map, the distance between China and New Sweden is 4.5

centimeters. Use the map of Maine to find the distance between the towns of China and New Sweden. Write and solve a proportion to find the distance between the towns.

1

65

4.5

d=

1d = 65 x 4.5

d = 292.5

centimeters

kilometers

The actual distance between China and

New Sweden is about 292.5 kilometers.

ANSWER

SOLUTION

Use the map to find the distance (in kilometers) between Paris and Marshfield. On the map the distance between Paris and Marshfield is 3.85 centimeters. Write and solve a proportion to find the distance d between the towns.

The actual distance between Paris and Marshfield

is about 250 kilometers.

ANSWER

165

3.85d

=

1d = 3.85 x 65

d = 250.25

centimeters

kilometers

The scale on a map is 1 cm : 12 km. Find the actual distance in kilometers for the given length on the map.4

cm

7.25 cm

6 cm

x

412

1

12

1

12

1

x

25.7

x

6

x = 12 x 4; 48 km

=

=

= X = 12 x 7.25; 87 km

X = 12 x 6 ; 72 km

You Try:

Scale DrawingsStrawberry Point, Iowa, has a strawberry sculpture that is 15 feet tall. If the scale of this model is 10 feet to 1 inch. How tall was the original strawberry?

Solutionstrawberry orignal of

model strawberry of

Height

HeightScale

in

15

1

10

h

ft

in

ft

H = 1.5 inches

The original strawberry was 1.5 inches

ANSWER

Finding a Dimension on a Scale ModelThere is a scale model of the White House in Tobu World

Square in Japan. The scale used for the model is 1 : 25. The height of the main building of the White House is 85 feet. Find this height on the model.

125

h85

=

1 x 85 = 25 h

3.4 = h

scale model

building

Cross products property

Divide each side by 25.

The height of the main building of the model is 3.4 feet.

ANSWER

SOLUTION

The model of the Eiffel Tower in Paris is 12 meters high. Use the scale factor of 1 : 25 in to estimate the height of the actual Eiffel Tower.

ANSWER

The height of Eiffel Tower is about 300 m.

SOLUTION

125

12h

=

1h = 25 x 12

h = 300

scale model

Eiffel Tower

Cross products property

Models of buildings in Detroit, Michigan were created by using a scale of 1 in. : 50 ft.

Find the height of the model in inches for the given height of the building.

Marriott Hotel: 725 ft.

Book Tower: 472 ft.

50

1

50

1

472

x

725

x14.5 inches

9.44 inches

=

=

You try:

Practice:Scale

Drawing Workshee

t