Virginia SOL Math / Grade 6 / Patterns, Functions & Algebra

6.PFA.1

Ratios

What you'll learn

  • Represent a relationship between two quantities as a ratio
  • Write ratios in different forms
  • Find equivalent ratios

Words to know

Ratio —
a comparison of two quantities
Term —
one of the numbers in a ratio
Equivalent ratio —
a ratio that names the same comparison
Rate —
a ratio comparing quantities with different units
Simplest form —
a ratio with no common factor above 1

Why it matters Ratios compare amounts fairly, like mixing paint colors, cooking for a crowd, or reading a map scale.

Worked examples

Model ItI do

There are 3 apples and 5 oranges. Write the ratio of apples to oranges.

A ratio compares the two amounts in order: apples to oranges is 3 to 5. It can also be written as 3:5 or 3/5.

Try It TogetherWe do

Write a ratio equivalent to 2:3 by doubling.

Multiply both terms by the same number. Doubling 2:3 gives 4:6, which is an equivalent ratio.

Now YouYou do

A class has 4 boys and 6 girls. Write the ratio of boys to girls in simplest form.

Write the ratio, then divide both terms by their common factor. Check your answer in the back of this chapter.

Practice

Mastered 0 of 11

Warm-up

Ease in with the basics.

  1. 1.Write the ratio of 4 cats to 3 dogs.

  2. 2.Simplify the ratio 4:8.

  3. 3.Write a ratio equivalent to 2:5 by doubling.

On Level

The core Quick Check from the book.

  1. 1.Write the ratio of 5 dogs to 2 cats.

  2. 2.Write a ratio equivalent to 1:4 by multiplying by 3.

  3. 3.Simplify the ratio 6:9.

  4. 4.There are 8 red and 12 blue marbles. Write the ratio of red to blue in simplest form.

  5. 5.Write the ratio 10 to 15 in simplest form.

Challenge

Stretch your thinking.

  1. 1.A recipe uses 3 cups of flour to 2 cups of sugar. In simplest form, what is the ratio of flour to sugar for a triple batch?

  2. 2.There are 15 boys and 20 girls in a class. Write the ratio of boys to girls in simplest form.

  3. 3.The ratio of red to blue tiles is 5:3. If there are 25 red tiles, how many blue tiles are there?