Ratios and Proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you find the unit rate?

Back

To find the unit rate, divide the total amount by the number of units. For example, if you spend $3.75 for 3 pounds, the unit rate is $3.75 ÷ 3 = $1.25 per pound.

Front

What does it mean for a relationship to be proportional?

Back

A relationship is proportional if two quantities maintain a constant ratio or rate.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common factor.

Front

What is the scale in a scale drawing?

Back

The scale in a scale drawing is the ratio of a distance on the drawing to the actual distance it represents.

Front

If a scale is 4 cm:9 ft, how do you find the actual length from the drawing?

Back

To find the actual length, set up a proportion using the scale. For example, if the drawing is 11 cm, the actual length is (11 cm * 9 ft) / 4 cm = 24.75 ft.

Front

What is the first step in solving a proportion?

Back

The first step in solving a proportion is to cross-multiply the terms.

Front

What does it mean if a table represents a proportional relationship?

Back

If a table represents a proportional relationship, the ratios of the corresponding values are equivalent.

Front

How do you express a ratio in simplest form?

Back

To express a ratio in simplest form, divide both parts of the ratio by their greatest common divisor.