Fraction multiplication

How to Multiply Three Fractions

Three fractions do not need a new rule. Multiply every numerator, multiply every denominator, then simplify: 1/2 × 2/3 × 3/4 = 6/24 = 1/4. The extra work is the extra numbers — products grow quickly, so cancelling shared factors across all three fractions is the difference between a short calculation and a large one.

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Quick answer

Same multiply-across rule, more cancelling

  1. 1. Treat it as one product. Three fractions sit in a single expression. You do not need a common denominator, and you do not need a new method.
  2. 2. Cancel across all three first. Any numerator can cancel with any denominator. Do that before the numbers grow.
  3. 3. Multiply and simplify. Multiply the leftover numerators, multiply the leftover denominators, then reduce if anything still shares a factor.

Interactive tool

Multiply fractions step by step

Type the problem directly or adjust the factors below. The tool rewrites mixed numbers and whole numbers, simplifies when possible, and shows every multiplication step.

Result

5/12

Multiply fractions by multiplying across. Multiply the numerators, multiply the denominators, and simplify at the end.

Treat each fraction as equal-size pieces. Count how many pieces stay selected after multiplying, then simplify if possible.

Rewritten

2/3 x 3/4 x 5/6

Simplify first

1/1 x 1/2 x 5/6

Before final simplify

5/12

Mixed-number form

Not needed

Formula flow

23×34×56=2131×3142×56=11×12×56=1 × 1 × 51 × 2 × 6=512

Step by step

Multiply across

  1. 1.2/3 x 3/4 x 5/6
  2. 2.factor A:2, factor B:4 ÷ 2
  3. 3.factor B:3, factor A:3 ÷ 3
  4. 4.2/3 x 3/4 x 5/6 -> 1/1 x 1/2 x 5/6
  5. 5.1 x 1 x 5 = 5
  6. 6.1 x 2 x 6 = 12
  7. 7.5/12

Multiply across: Fraction multiplication does not need common denominators. The operation tracks part of a part, so multiplying across keeps the size relationship intact.

Worked example

Multiply 1/2 × 2/3 × 3/4

1/2 × 2/3 × 3/4 = (1 × 2 × 3)/(2 × 3 × 4) = 6/24 = 1/4

Three fractions, one rule. Multiply every numerator (1 × 2 × 3 = 6) and every denominator (2 × 3 × 4 = 24), then simplify 6/24 to 1/4. You could also cancel first: the 2s cancel, the 3s cancel, and you are left with 1/4 without ever building 6/24.

Worked example

Cancel first with 2/3 × 3/4 × 5/6

2/3 × 3/4 × 5/6 = 1/1 × 1/2 × 5/6 = 5/12

A numerator can cancel with any of the three denominators, not only the one next to it. The first 3 cancels the second 3, and the 2 cancels with the 4. After cancelling, the leftover product is 1 × 1 × 5 over 1 × 2 × 6 = 5/12.

Worked example

Multiply 3/5 × 1/2 × 4/9

3/5 × 1/2 × 4/9 = 1/5 × 1/2 × 4/3 = 4/30 = 2/15

The 3 in the first numerator shares a factor with the 9 in the third denominator, so cancel those first. Then 4 and 2 share a factor of 2. The leftover product 1 × 1 × 2 over 5 × 1 × 3 is 2/15 — much smaller than multiplying 3 × 1 × 4 = 12 over 5 × 2 × 9 = 90 and reducing 12/90 afterwards.

Worked example

Three unit fractions: 1/2 × 1/3 × 1/4

1/2 × 1/3 × 1/4 = 1/24

Unit fractions have 1 in every numerator, so there is nothing to cancel on top. Multiply the denominators: 2 × 3 × 4 = 24, and the product is 1/24. That picture is useful: each extra unit fraction cuts the previous piece into smaller equal parts, so the whole ends up in 24 pieces.

Why three fractions still use the same rule

Multiplying two fractions takes a part of a part. Adding a third fraction takes a part of that result. 1/2 × 1/3 × 1/4 means one half of one third of one fourth: each extra fraction cuts the previous piece again, so the denominators multiply (2 × 3 × 4 = 24) and you keep 1 × 1 × 1 of those pieces. The picture scales; the rule does not change.

That is also why grouping does not matter. Compute 1/2 × 2/3 first to get 1/3, then multiply by 3/4 to get 1/4 — or multiply all three at once. Both paths land on the same product, because multiplication is associative.

Cancel across the whole product, not just neighbours

With two fractions, cancelling looks like a diagonal. With three, it is easier to forget that a factor in the first numerator can cancel a factor in the third denominator. Write every numerator in one list and every denominator in another, then strike matching factors wherever they sit.

2/3 × 3/4 × 5/6

= (2 × 3 × 5) / (3 × 4 × 6)

= (1 × 1 × 5) / (1 × 2 × 6)

= 5/12

The 3s cancel, then 2 and 4 reduce to 1 and 2. Nothing in 5/12 still shares a factor, so that is the finished answer. Skipping the cancel step would send you through 30/72 first — the same fraction, much more arithmetic.

When one of the three is not a plain fraction

Homework often mixes types: 2 × 3/4 × 5/6, or 1 1/2 × 2/3 × 4/5. Rewrite the odd one out first. A whole number becomes a fraction over 1, and a mixed number becomes an improper fraction. After that, the expression is three ordinary fractions again, and the same cancel-then-multiply path applies.

Do not multiply the two fractions and then try to handle the mixed number as a leftover. Convert first so every factor is in the same form; mixing formats is where most three-factor mistakes start.

Common mistakes with three fractions

  • Only cancelling neighbouring pairs: a numerator can cancel with any denominator in the product. Look across all three fractions before multiplying.
  • Multiplying two, then adding the third: every sign in the expression is multiplication. 1/2 × 2/3 × 3/4 is not (1/2 × 2/3) + 3/4.
  • Skipping simplification: three-fraction products hide shared factors easily. Cancel early, then check the leftover product one more time.

Common questions

Multiplying Three Fractions FAQ

Use the same multiply-across rule as two fractions. Multiply all three numerators together, multiply all three denominators together, then simplify. For 1/2 × 2/3 × 3/4, that is (1 × 2 × 3)/(2 × 3 × 4) = 6/24 = 1/4.