Scale Factor

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. It is used to determine the ratio of the dimensions of a scale drawing to the actual dimensions.

Front

How do you calculate the unit rate?

Back

To calculate the unit rate, divide the total amount by the number of units. For example, if a company pays $450 for 4 employees working 15 hours each, the unit rate is $450 ÷ (4 employees × 15 hours) = $7.50 per hour.

Front

If a scale drawing shows a car length of 3 cm and the scale is 1 cm:4 ft, what is the actual length of the car?

Back

The actual length of the car is 3 cm × 4 ft/cm = 12 feet.

Front

What is the formula to find the actual distance using a map scale?

Back

Actual Distance = Map Distance × (Scale Factor). For example, if the map distance is 4.125 inches and the scale is 2 inches = 40 miles, then Actual Distance = 4.125 inches × (40 miles / 2 inches) = 82.5 miles.

Front

What does a scale of 1.5 inches = 2 feet mean in a blueprint?

Back

It means that every 1.5 inches on the blueprint represents 2 feet in real life.

Front

How do you find the length of a room in a blueprint if you know the actual length?

Back

To find the length on the blueprint, use the scale. For example, if the actual length is 17 feet and the scale is 1.5 inches = 2 feet, then Length on Blueprint = (17 feet × 1.5 inches) / 2 feet = 12.75 inches.

Front

What is the scale factor from a smaller triangle to a larger triangle if the sides are in the ratio 1:2?

Back

The scale factor is 2.

Front

If a map has a scale of 1 inch = 20 miles, how far apart are two cities that are 3 inches apart on the map?

Back

The actual distance is 3 inches × 20 miles/inch = 60 miles.

Front

What is the relationship between scale factor and area?

Back

If the scale factor is k, then the area of the scaled figure is k² times the area of the original figure.

Front

How do you convert a scale drawing measurement to actual measurement?

Back

Multiply the measurement on the scale drawing by the scale factor to get the actual measurement.