Scale Drawings 6.1.2.3 Determine the rate for ratios of quantities with different units

I can… Self Assessment Use scale drawings to find actual lengths 5- I can do it without help & teach others. 4- I can do this with no help, but I don’t know if I can explain it. 3- I can do this with a little help. 2- I can do this with a lot of help! 1- I don’t have a clue.

Vocabulary Scale: how the drawing’s dimensions and the actual dimensions are related Scale Drawing: a drawing that is similar but either larger or smaller than the actual object.

Scale Drawings First Things First… Lets get rid of some possible misconceptions we might have about this notion of scale. We are not talking about the kind of scale you might see in a grocery store

Scale Drawings First Things First… Lets get rid of some possible misconceptions we might have about this notion of scale. We are also not talking about the kind of scale you get on at a doctors office

Scale Drawings So What Are We Talking About We are talking about the kind of scale that shows the relationship between two objects. Examples might include: Models Blueprints for House Maps

Scale Drawings Where Will I See This Some careers or jobs that utilize the math concept of scale include: Mapmakers (Cartographers) Doctors Model Makers Engineers Contractors Construction Workers Artists Pilots Truck Drivers Fashion/Clothes Designers Architects

Scale Model : Actual Model Scale Drawings The standard way to write a scale is scale model to actual object Scale Model : Actual Model Scale Model Actual Model Scales are written using a colon or as a fraction

Scale Model : Actual Model Scale Drawings Example 1: A drawing of a car that is drawn to scale is 1:20. If the drawing of the car is 12 inches long, what is the length of the car in real-life? HINT: Find equivalent fractions Scale Model : Actual Model 1 : 20 12 : ___ Ask, “1 times what number equals 12?” X 12 X 12 240 inches

Scale Model : Actual Model Scale Drawings HINT: Find equivalent fractions Example 2: On a map of the United States the scale is 1 inch = 100 miles. If the distance from Clinton to Greensboro is 4 inches on the map, how many miles apart are the two cities? Scale Model : Actual Model 1 inch: 120 miles 4 inches : ___ X 4 X 4 Ask, “1 times what number equals 4?” 400 miles

Scale Model : Actual Model Scale Drawings HINT: Find equivalent fractions Example 3: You are building a model boat with a scale of 1 in : 2 ft. The actual boat is 18 feet long. How long should you make your model? Scale Model : Actual Model 1 inch: 2 feet ___inches : 18 feet X 9 X 9 9 inches

Scale Model : Actual Model Your turn… HINT: Find equivalent fractions Example 4: An 8 inch picture of a doll is larger than its true size a t a scale of 4 in: 3 in. How tall is the actual doll in inches? Scale Model : Actual Model 4 inch: 3 inches 8 inches : ___ inches X 2 X 2 6 inches

Scale Model : Actual Model Your turn… HINT: Find equivalent fractions Example 5: The length of a wall on a sale drawing is 192 millimeters. The scale on the drawing is 8mm : 2m. Find the actual length. Scale Model : Actual Model 8 mm: 2 m 192 mm : ___ m X 24 X 24 48 meters

Scale Model : Actual Model Your turn… HINT: Find equivalent fractions Example 6: An airplane model uses the scale 1 in : 32 in. The actual airplane is 512 inches long. How long is the model? Scale Model : Actual Model 1 in: 32 in ___ in : 512 in X 16 X 16 16 inches

I can… Self Assessment Use scale drawings to find actual lengths 5- I can do it without help & teach others. 4- I can do this with no help, but I don’t know if I can explain it. 3- I can do this with a little help. 2- I can do this with a lot of help! 1- I don’t have a clue.

in your math notebook Daily Check 2.3 The scale on a map is 1 in: 200 mi. Find the actual distance, in miles, for a length of 2 inches on the map. A model has a scale of 1 in : 15 ft. Find the length of the model, in inches for an actual length of 75 ft. A drawing has a scale of 2 in : 12 ft. Make a table to show what lengths in the scale drawing correspond to the actual lengths of 18 feet, 24 feet, and 36 feet. Scale Drawing length Actual Length 18 feet 24 feet 36 feet