Multiplying Fractions Examples in Math

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Multiplying Fractions.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Math.

Concept Recap

To multiply fractions, multiply the numerators together and the denominators together: abร—cd=aร—cbร—d\frac{a}{b} \times \frac{c}{d} = \frac{a \times c}{b \times d}. Simplify the result by cancelling common factors.

23ร—34\frac{2}{3} \times \frac{3}{4} means 'two-thirds of three-quarters.' Take 34\frac{3}{4} of something, then take 23\frac{2}{3} of that result.

Read the full concept explanation โ†’

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Multiplying fractions multiplies the tops and the bottoms โ€” it means taking a fraction of a fraction.

Common stuck point: The procedure for multiplying fractions is the easy part; the trap is finding a common denominator before multiplying. Asking "Am I taking a part of a part, multiplying tops and bottoms straight across?" first is what keeps a correct-looking calculation from being attached to the wrong concept.

Sense of Study hint: Ask: Am I taking a part of a part, multiplying tops and bottoms straight across?

Worked Examples

Example 1

easy
Multiply 23ร—57\frac{2}{3} \times \frac{5}{7}.

Answer

1021\frac{10}{21}

First step

1
Multiply the numerators: 2ร—5=102 \times 5 = 10.

Full solution

  1. 2
    Multiply the denominators: 3ร—7=213 \times 7 = 21.
  2. 3
    The product is 1021\frac{10}{21}, which is already in simplest form since gcdโก(10,21)=1\gcd(10, 21) = 1.
To multiply fractions, multiply numerator by numerator and denominator by denominator. No common denominator is needed, unlike addition.

Example 2

medium
Compute 49ร—38\frac{4}{9} \times \frac{3}{8}.

Example 3

easy
Multiply 27ร—34\frac{2}{7} \times \frac{3}{4} and simplify if possible.

Example 4

medium
Compute 313ร—353\frac{1}{3} \times \frac{3}{5}.

Example 5

medium
Compute 214ร—1132\frac{1}{4} \times 1\frac{1}{3}.

Example 6

hard
Solve for xx: 35ร—x=920\frac{3}{5} \times x = \frac{9}{20}.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
Multiply 35ร—29\frac{3}{5} \times \frac{2}{9}.

Example 2

medium
A tank is 34\frac{3}{4} full. If 25\frac{2}{5} of the water is used, what fraction of the tank is still full?

Example 3

easy
Compute 12ร—13\frac{1}{2} \times \frac{1}{3}.

Example 4

easy
Compute 23ร—45\frac{2}{3} \times \frac{4}{5}.

Example 5

easy
Compute 34ร—23\frac{3}{4} \times \frac{2}{3}.

Example 6

easy
Compute 14ร—8\frac{1}{4} \times 8.

Example 7

easy
Compute 25ร—52\frac{2}{5} \times \frac{5}{2}.

Example 8

easy
Compute 12ร—12\frac{1}{2} \times \frac{1}{2}.

Example 9

easy
Compute 310ร—56\frac{3}{10} \times \frac{5}{6}.

Example 10

easy
Compute 05ร—78\frac{0}{5} \times \frac{7}{8}.

Example 11

medium
Compute 212ร—342\frac{1}{2} \times \frac{3}{4}.

Example 12

medium
Compute 68ร—49\frac{6}{8} \times \frac{4}{9}.

Example 13

medium
Compute 23\frac{2}{3} of $45\$45.

Example 14

medium
Compute 35ร—109\frac{3}{5} \times \frac{10}{9}.

Example 15

medium
Compute 12ร—23ร—34\frac{1}{2} \times \frac{2}{3} \times \frac{3}{4}.

Example 16

medium
Compute (23)3\left(\frac{2}{3}\right)^3.

Example 17

medium
A recipe calls for 34\frac{3}{4} cup flour. If you make 23\frac{2}{3} of the recipe, how much flour?

Example 18

medium
Compute 45ร—1516\frac{4}{5} \times \frac{15}{16}.

Example 19

medium
Compute 38รท14\frac{3}{8} \div \frac{1}{4}.

Example 20

challenge
Compute 12ร—34ร—56ร—78\frac{1}{2} \times \frac{3}{4} \times \frac{5}{6} \times \frac{7}{8}.

Example 21

challenge
What is the product of the first 5050 terms: 12โ‹…23โ‹…34โ‹ฏ5051\frac{1}{2} \cdot \frac{2}{3} \cdot \frac{3}{4} \cdots \frac{50}{51}?

Example 22

challenge
Find ab\frac{a}{b} such that abร—35=110\frac{a}{b} \times \frac{3}{5} = \frac{1}{10} where gcdโก(a,b)=1\gcd(a, b) = 1.

Example 23

easy
Compute 13ร—15\frac{1}{3} \times \frac{1}{5}.

Example 24

easy
Compute 34ร—12\frac{3}{4} \times \frac{1}{2}.

Example 25

easy
Compute 56ร—07\frac{5}{6} \times \frac{0}{7}.

Example 26

easy
Compute 45ร—1\frac{4}{5} \times 1.

Example 27

medium
Compute 89ร—34\frac{8}{9} \times \frac{3}{4}.

Example 28

medium
Compute 710ร—514\frac{7}{10} \times \frac{5}{14}.

Example 29

medium
Find 38\frac{3}{8} of $64\$64.

Example 30

medium
Compute 512ร—815\frac{5}{12} \times \frac{8}{15}.

Example 31

medium
Compute (34)2\left(\frac{3}{4}\right)^2.

Example 32

medium
A pitcher holds 56\frac{5}{6} L of juice. If 35\frac{3}{5} of it is poured out, how much was poured?

Example 33

medium
Compute 29ร—92\frac{2}{9} \times \frac{9}{2}.

Example 34

hard
Compute 78ร—1621\frac{7}{8} \times \frac{16}{21}.

Example 35

hard
A garden is 34\frac{3}{4} acre. 25\frac{2}{5} of it is planted with corn, and 13\frac{1}{3} of that corn area is sweet corn. What fraction of the garden is sweet corn?

Example 36

hard
Compute 23ร—34ร—45ร—56\frac{2}{3} \times \frac{3}{4} \times \frac{4}{5} \times \frac{5}{6}.

Example 37

hard
A recipe makes 45\frac{4}{5} kg of cookies and you want to make 23\frac{2}{3} of the recipe. How many kg of cookies?

Example 38

hard
Compute 1516ร—825\frac{15}{16} \times \frac{8}{25}.

Example 39

challenge
Compute the product โˆk=210kโˆ’1k\prod_{k=2}^{10} \frac{k-1}{k} (that is, 12โ‹…23โ‹ฏ910\frac{1}{2}\cdot\frac{2}{3}\cdots\frac{9}{10}).

Example 40

challenge
Find positive integers a,ba, b in lowest terms with gcdโก(a,b)=1\gcd(a,b)=1 so that abร—712=13\frac{a}{b} \times \frac{7}{12} = \frac{1}{3}.

Background Knowledge

These ideas may be useful before you work through the harder examples.

fractionsmultiplication