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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
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