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

2. 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.

3. 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.

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. Scale Model : Actual Model
Your turn…
HINT: Find equivalent fractions
Example 6: An airplane model uses the scale 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

15. 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.

16. in your math notebook Daily Check 2.3
The scale on a map is in: 200 mi. Find the actual distance, in miles, for a length of 2 inches on the map.
A model has a scale of 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