1. How to Scale

2. Why is scaling important?
Imagine if you had to draw a “full-size” map of the United States!
How much paper would it require?
How much time would it take?
Scaling allows us to take large objects or long distances and “shrink” them to a smaller size

3. All Maps Include a Scale Bar

4. Scales give you an equivalence factor
Ex: 1 inch = 200 miles
Ex: 1 centimeter = 3 meters

5. Okay, so how do I scale? Figure out what scale you want to use first.
For our notes we will use 1 cm = 5 m, but you will get the chance to make up your own scale later
Measure the actual (real) distance
Convert the real distance to a scaled distance

6. A Sample Problem
In a local park, the swings are 15 meters away from the slide. If I draw a scaled map of the park, how far apart from the swings should I draw the slide?
Step 1: What’s the scale?
Let’s use 1 cm = 5m
Step 2: What’s the real distance?
15 meters between the swings and the slide

7. = 1 cm 5 m x cm 15 m Step 3: What’s the scaled distance?
We need to do a conversion
1 cm
5 m =
x cm
15 m

8. Cross multiply
1 cm
5 m =
x cm
15 m
(1) (15) = (5) (x)

9. Solve for “x”
(1) (15) = (5) (x) 5
x = 3 cm
You should draw the slide 3 cm away from the swings on your map

10. Practice
Main Street at Disneyland is 225 m long. Use the same scale (1 cm = 5 m) to determine how long you should draw Main Street on a map of Disneyland.

11. RoundRobin Begin with partner who has the shiniest shoes.
Explain to your partner the steps you followed to solve the problem.
Thank your partner.
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