Bell Work Write the equivalent rate. 1. $ 12 $ ? 3. 150 miles ? miles 1 hours $ 12 = 1 minute $ ? 3. 1 day 150 miles = 1 week ? miles ANSWER 1050 mi ANSWER $.20 2. 2 pints 1 person = ? cups 4. 320 calories 1 cup = ? calories 1 fluid ounce Hint: 1 pint = 2 cups Hint: 1 cup = 8 fluid ounces ANSWER 40 cal ANSWER 4 c

Scale Drawings

Review Solve the proportion. Then check your solution. b 1.8 = 49.6 14.4 14.4b = 1.8(49.6) Cross products property 14.4b = 89.28 Multiply. 14.4 89.28 = b Divide each side by 14.4. = b 6.2

Review Use the cross products property to solve the proportion. 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 A teacher can grade 4 tests in 25 minutes. At this rate, how long will it take her to grade 36 tests? ANSWER 225 min 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 Drawing A 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.

Scale In 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.

Using the Scale of a Map centimeters kilometers On 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. SOLUTION 1 65 4.5 d = centimeters kilometers 1d = 65 x 4.5 d = 292.5 The actual distance between China and New Sweden is about 292.5 kilometers. ANSWER

centimeters kilometers 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. SOLUTION 1 65 3.85 d = centimeters kilometers 1d = 3.85 x 65 d = 250.25 The actual distance between Paris and Marshfield is about 250 kilometers. ANSWER

You Try: 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 x = 12 x 4; 48 km = 7.25 cm X = 12 x 7.25; 87 km = 6 cm X = 12 x 6 ; 72 km =

Scale Drawings Strawberry 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?

Solution H = 1.5 inches The original strawberry was 1.5 inches ANSWER

Finding a Dimension on a Scale Model There 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. SOLUTION 1 25 h 85 = scale model building 1 x 85 = 25 h Cross products property 3.4 = h Divide each side by 25. The height of the main building of the model is 3.4 feet. ANSWER

Cross products property 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. SOLUTION scale model Eiffel Tower 1 25 12 h = 1h = 25 x 12 Cross products property h = 300 ANSWER The height of Eiffel Tower is about 300 m.

You try: 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. = 14.5 inches Book Tower: 472 ft. = 9.44 inches

Scale Drawing Worksheet Practice: Scale Drawing Worksheet