**Basics**

Scale refers to the ratio of image size to actual size.

To answer questions regarding scale, you will often need to work with ratio and proportion.

In order to cross-multiply, it is helpful to understand algebraic equations. It is also helpful to know your multiplication and division tables.

**
Question
**In the map above, the ratio of distance = 1 inch to 300 miles = 1:300 = .

How many miles do 4 inches on the map represent?

**Answer
**1200 miles

**Answer Process
**To solve for an unknown variable in proportionate ratios, cross-multiply.

=

For ratios and **→**

ad = bc

ad = 1 × d

bc = 300 × 4

1 × d = 300 × 4

1d = 1200

d = 1200

Question

In the map above, the ratio of distance = 1 inch to 300 miles = 1:300 = .

Also in the map, Jackson, Mississippi and Columbia, South Carolina are approximately 2 inches apart. In the real world, approximately how many miles are Jackson and Columbia apart?

**Answer**

600 miles

**Answer Process
**To solve for an unknown variable in proportionate ratios, cross-multiply.

=

For ratios and **→**

ad = bc

ad = 1 × d

bc = 300 × 2

1 × d = 300 × 2

1d = 600

d = 600

**
Practice – Questions
**1. In the map above, the ratio of distance = 1 inch to 300 miles = 1:300 = .

How many miles do 6 inches on the map represent?

2. In the map above, the ratio of distance = 1 inch to 300 miles = 1:300 = .

Also in the map, Columbus, Ohio and Tallahassee, Florida are approximately 3 inches apart. In the real world, approximately how many miles are Columbus and Tallahassee apart?

3. In the map above, the ratio of distance = 1 inch to 300 miles = 1:300 = .

Also in the map, Montgomery, Alabama and Montpelier, Vermont are approximately 5 inches apart. In the real world, approximately how many miles are Montgomery and Montpelier apart?

4. In the image below, a cow is 1 inch long. In the real world, a cow is 60 inches long. Using a colon, write a scale representing this cow.

5. In the image below, a cow is 1 inch long. In the real world, a cow is 60 inches long. Using a fraction, write a scale representing this cow.

Practice – Answers

1. 1800

2. 900

3. 1500

4. 1:60

5.