Scale Factor

Organizer

What is it? Find a Scale Factor

#1 Rule Real Word Problem

Scale Factor

What is it?

• Scale Factor is the number you multiply to enlarge or reduce shapes or ratios.

• Example: Make something TWICE AS BIG has a scale factor of 2 because you multiplied by 2.

How to Find the Scale Factor

• In Math, Divide the larger number by the smaller number.

• In Real World, look for a KEY, SCALE, or LEGEND. It will tell you the scale factor

Example

Model Size Actual Size

Size 1 ft long 80 ft long

A Model Airplane vs Real Airplane

Example

Blueprint Size Actual Size

Size 2.5 ft long 145 ft long

Blueprint of House vs Actual House

Example

Map Size Actual Size

Size 2.3 ft long 15206400 ft long

Map of U.S.A. vs Actual U.S.A.

Example

Toy Size Actual Size

Size 0.9 ft long 151 ft long

Toy Statue of Liberty vs Actual Statue

Real World Problem

• Create a Proportion.Fraction 1 = Fraction 2

• Fraction 1 = the scale factor as a fraction• Fraction 2 = size of model

Actual size

• Solve for x.

One of those will be an x

Example

Example

The scale on a road map is 1 cm = 500 miles. If the distance on the map between New York City and Memphis is 2.2 cm, what is the actual distance between the two cities?

Example

On a scale drawing, a helicopter is 2.2 ft long. The scale factor is 1/9. Find the length of the helicopter.

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