Year One

MathsFractions

Maths | Year 5 | Fractions | Multiply Fractions | Lesson 2 of 2: Bubble Blast

Success Criteria

Aim• I can multiply mixed numbers by whole numbers.

• I can show that multiplication is the same as repeated addition.

• I can use fraction diagrams to multiply fractions by whole numbers.

• I can convert between improper fractions and mixed numbers.

Fraction Bubble BurstPop the bubbles which are proper fractions.

148

23

158

73

14

672

49513

4

78

Fraction Bubble BurstPop the bubbles which are improper fractions.

495

14

158

78

23

672

14813

4

73

Fraction Bubble BurstPop the bubbles which are mixed numbers.

148

134

78

14

23

672

49515

8

73

Multiplying Proper Fractions

Multiplying a fraction by a whole number is the same as repeated addition.

27

× 5

The numerator is multiplied by the whole number.

2 × 5 = 10

The denominator is multiplied by one.

7 × 1 = 7

+27

+27

+27

+27

=27

107

Multiplying Proper Fractions

There are different strategies to multiply a mixed number by a whole number. One strategy is repeated addition.

127 × 2

The numerator is multiplied by the whole number.

2 × 2 = 4

The denominator is multiplied by one.

7 × 1 = 7

+127 127 = 247

The whole is multiplied

by the whole number.1 × 2 = 2

Multiplying Mixed Numbers

=14

× 2294

× 2 =184

=24

4

In this mixed number, every whole is made

of four parts.(2 × 4) + 1 = 9

The numerator is multiplied by the whole number.

9 × 2 = 18

This answer is an improper fraction. We need to change it to a

mixed number.

The denominator is multiplied by one.

4 × 1 = 4

18 ÷ 4 = 4 r 2

To multiply a mixed number by a whole number, you can also change the mixed number into an improper fraction.

=47

× 31117

× 3 =337

=57

4

In this mixed number, every whole is made

of four parts.(1 × 7) + 4 = 11

The numerator is multiplied by the whole number.

11 × 3 = 33

This answer is an improper fraction. We need to change it to a

mixed number.

The denominator is multiplied by one.

7 × 1 = 7

33 ÷ 7 = 4 r 5

Multiplying Mixed NumbersTo multiply a mixed number by a whole number, you can also change the mixed number into an improper fraction.

Another strategy to multiply a mixed number by a whole number is to partition the whole and the fraction.

+

56

× 42

56

206

× 4 =

=206

Partition the mixed number into a whole

and a fraction.Multiply the whole and then multiply

the fraction.

Add them back together to find

the answer.

Multiplying Mixed Numbers

2

8 8 206 = 11 26 or 11 13

× 4 = 8

Fraction Flowers Bingo

Word Up

=23

× 4153

× 4 =203

=23

6

Four friends shared a takeaway.

Each person ate 1 23 pizzas each.

How much pizza was eaten in total?

Word Up

=58

× 61138

× 6 =788

=68 km9

Six friends took part in a sponsored swim.

They each swam 1 58 km.

How many kilometres did they swim in total?

Success Criteria

Aim• I can multiply mixed numbers by whole numbers.

• I can show that multiplication is the same as repeated addition.

• I can use fraction diagrams to multiply fractions by whole numbers.

• I can convert between improper fractions and mixed numbers.