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Copyright © Ed2Net Learning, Inc.1 Proportion & Scale Drawings Grade 6
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Copyright © Ed2Net Learning, Inc.2 Find the unit rate: 1. 200 miles in 5 hours 2. $6.20 for 5 pounds 3. 2 cups for 36 cookies 4. 150 tickets in 5 days 5. 24 people in 8 cars Warm up
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Copyright © Ed2Net Learning, Inc.3 Let Us Review our last lesson A rate is a ratio that is used to compare different kinds of quantities. A unit rate describes how many units of the first type of quantity corresponds to one unit of the second type of quantity. A unit price is a rate comparing the price of an item to its unit of measure. To find the unit price divide the total cost by the number of items bought.
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Copyright © Ed2Net Learning, Inc.4 Let Us Review Rate = Distance/time To find rate divide distance by time Time = Distance/rate To find time divide distance by rate
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Copyright © Ed2Net Learning, Inc.5 Find the population density of a county with 56,000 residents and an area of 636 square miles. About 88 people per square mile Example
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Copyright © Ed2Net Learning, Inc.6 What is a Proportion? A proportion is an equation that states that two ratios are equal. Proportions always have a equal sign. Example of proportion: 2 6 3 9 = Let’s get Started
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Copyright © Ed2Net Learning, Inc.7 We can write proportions in two ways: In a proportion 2:3 = 6:9 First and last terms (i.e. 2 and 9) are called extremes. Second and third terms (i.e. 3 and 6) are called means. Rule: In a proportion, the product of the means equals to the product of the extremes. Or 2:3 = 6:9 2 6 3 9 =
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Copyright © Ed2Net Learning, Inc.8 Scale Drawings What is a scale drawing? A scale drawing is a drawing of an object with dimensions proportional to those of the actual object. The scale of the drawing is the ratio of the size of the drawing to the actual size of the object. Architects and map-makers use scale drawings.
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Copyright © Ed2Net Learning, Inc.9 Example 1 On a map 1 in = 2 mile, What does 5 in equals?. You can establish a proportion: Now cross-multiply, we will get 1 x x = 2 x 5 After simplification we will get. x = 10 miles. 1 5 2 x =
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Copyright © Ed2Net Learning, Inc.10 Example 2 On a scale drawing if 1 in = 20 yards, What does 100 yards equals?. You can establish a proportion: Now cross-multiply, we will get 1 x 100 = y x 20 After simplification we will get. 100 = 20y so y = 5 in 1 y 20 100 =
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Copyright © Ed2Net Learning, Inc.11 Let’s take a break!!
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Copyright © Ed2Net Learning, Inc.12
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Copyright © Ed2Net Learning, Inc.13 Your Turn On a scale drawing if 1 inch = 3 feet then : 1. 4 inches = 2. 3 inches = 3. 10 inches = 4. 1/3 inch = 5. 12 inches =
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Copyright © Ed2Net Learning, Inc.14 Your Turn Solve: 6. A computer circuit board 4 cm wide ; 1 cm: 0.2 cm 7. 15feet by 25feet 8. 6/13 = 8/n 9. A garage door 16feet wide ; 2 inches: 1 foot 10. A gear 3 5/8 in. across; 4in: ½ in.
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Copyright © Ed2Net Learning, Inc.15 1. Out of every 100 U.S. households having teens, 8 of them will purchase camping equipment sometimes during the year. Of the 64.5million households having teens in the U.S., How many will purchase camping equipment during the year?
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Copyright © Ed2Net Learning, Inc.16 2. An invention by a NASA scientist Valerie Thomas may make TV’s have 3 – D images. A drawing for her patent of the illusion transmitter is 8.4cm. Tall. If the scale is 1cm : 2.2 cm, what will the actual length of the transmitter be?
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Copyright © Ed2Net Learning, Inc.17 3. The first Jumbo Jet was the Boeing 747, which is 70.5 m long. The wingspan of a 747 is 60 meters. A model 747 has a wingspan of 80 cm. What should the length of the model be?
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Copyright © Ed2Net Learning, Inc.18 Let Us Review A proportion is an equation that states that two ratios are equal. We can write proportions in two ways. or 2:3 = 6:9 In a proportion, the product of the means equals to the product of the extremes. 2 6 3 9 =
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Copyright © Ed2Net Learning, Inc.19 Let Us Review A scale drawing is a drawing of an object with dimensions proportional to those of the actual object. The scale of the drawing is the ratio of the size of the drawing to the actual size of the object. Architects and map-makers use scale drawings.
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Copyright © Ed2Net Learning, Inc.20 You did Great Today! Be sure to practice what you have learned today
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