How_To_Be_Good_At_Math

NUMBERS • DIVIDING FRACTIONS 57

Division revision

Now it’s your turn! Try out your fraction division skills

with these tricky teasers.

TRY IT OUT

To write the number 3 as

a fraction, we make 3 the

numerator over a denominator

of 1, like this.

Let’s work out^1 / 2 ÷ 3. First,

we have to make the whole

number into a fraction.

Look at these calculations. Can

you see a pattern? We can make

the denominators of the answers by

multiplying the whole numbers and

the denominators together. We can

use this pattern to divide by fractions

without using a fraction wall.

Answers on page 319

How to divide a fraction by a whole number

There’s a simple way to divide a fraction by a

whole number – by turning things upside down!

When we write a whole number as a

fraction, the denominator is always 1

1 ⁄ 6 ÷ 2 =?

1 ⁄ 7 ÷ 3 =?

1 ⁄ 2 ÷ 5 =?

2 ⁄ 3 ÷ 4 =?

The denominator becomes the numerator

The ÷ sign changes to a × sign

1

2 ÷^3 = × =

1

2

1

3

1

6

Next, we turn our new

fraction upside down and

change the division sign into

a multiplication sign. So our

calculation is now^1 / 2 ×^1 / 3.

The whole number

becomes the numerator

The numerator becomes

the denominator

Now we just have to multiply

the two numerators, then

the two denominators, to get

the answer,^1 / 6.

1

2

3

1

÷

1

2

1

3

= ×

3 =

3

1

If we multiply the

original denominator

by the whole number,

we get the new

denominator

If we multiply 4 and 3

together, we get 12

1

2 ÷^3 =?

1

2

1

÷ 8 = 16

1

4

1

÷ 3 = 12

1

3

1

÷ 2 = 6

056-057_Dividing_Fractions.indd 57 29/02/2016 14:09