ratios and proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, 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 price per gallon if you know the total cost and the number of gallons?

Back

Divide the total cost by the number of gallons. For example, if it costs $46.80 for 13 gallons, the price per gallon is $46.80 ÷ 13 = $3.60.

Front

What does it mean for two quantities to be proportional?

Back

Two quantities are proportional if they maintain a constant ratio or rate.

Front

How can you determine if a table shows a proportional relationship?

Back

Check if the ratios of corresponding values are equal. If they are not, the relationship is nonproportional.

Front

What is the formula for solving a proportion?

Back

Cross-multiply the two ratios and set them equal to each other. For example, if a/b = c/d, then a*d = b*c.

Front

What is the ratio of STARS to SQUARES if there are 3 STARS and 4 SQUARES?

Back

The ratio of STARS to SQUARES is 3 to 4.

Front

What is the difference between proportional and nonproportional relationships?

Back

In proportional relationships, dividing one quantity by another gives the same result, while in nonproportional relationships, the result varies.

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the ratio of flour to sugar?

Back

The ratio of flour to sugar is 2 to 3.

Front

How do you simplify a ratio?

Back

Divide both terms of the ratio by their greatest common divisor (GCD). For example, the ratio 4:8 simplifies to 1:2.