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Lesson overview

Number - fractions

Multiplying a fraction by a whole number means taking that fraction several times. We can think of repeated addition or of groups of equal fractional parts.

Repeated fractional parts

3 x $\frac{1}{4}$ means $\frac{1}{4}$ + $\frac{1}{4}$ + $\frac{1}{4}$ .

The denominator stays the same because the size of the part stays the same.

Multiply a mixed number

2 x $1\frac{1}{2}$ means two groups of one and one half.

Use repeated addition or convert to an improper fraction first.

Connect to an improper fraction

$4 x \frac{3}{5} = \frac{12}{5}.$

Sometimes the answer needs to be written as a mixed number too.

Worked example

Calculate 3 x $\frac{2}{3}$ .

Three groups of $\frac{2}{3}$ is $\frac{2}{3}$ + $\frac{2}{3}$ + $\frac{2}{3}$ .
Add the numerators because the thirds stay the same.
$\frac{6}{3}$ equals 2 wholes.
So the answer is 2.

Round 1: Learn it

Think of the multiplication as repeated addition of the same fraction.

Finish this round to unlock Round 2: Show you know it.

Question 1

What is 3 x $\frac{1}{4}$ ?

Question 2

What is 4 x $\frac{3}{5}$ ?

Question 3

What is 3 x $\frac{2}{3}$ ?

Question 4

What is 2 x $1\frac{1}{2}$ ?

Question 5

Which answer matches 5 x $\frac{1}{10}$ ?

Common mistakes

Watch for these as you work through the lesson.

Changing the denominator when multiplying by a whole number.
Multiplying the denominator as well as the numerator.
Leaving an answer improper when the question expects a mixed number.

Multiply proper fractions and mixed numbers by whole numbers, supported by materials and diagrams

Lesson overview

Worked example

Round 1: Learn it

Common mistakes

Related topics

Independent practice will plug in here