We have looked at how to write number sentences from stories with whole numbers. Remember that we can look for key words to tell us what operator to use.

Words for addition (+) include:

more than,
greater,
together,
another and
further

Words for subtraction (-) include:

less than,
fewer,
removed,
take away and
subtracted

Now watch this video to learn about using fraction knowledge to create number sentences.

Once you've written a number sentence, you can solve it to find the final answer. For example, you may need to add or subtract the fractions.

Remember!

Underline the key words in the story to help understand the mathematics.

A number sentence is a way to represent the mathematics with symbols.

Worked Examples

Question 1

$Paul$ had travelled one $eighth$ of the distance to school when he realised he had forgotten his $squash racquet$ and so went home to get it.

Complete the number sentence that describes how far in total $Paul$ has travelled by the time he arrives back at home.

$Paul$ has travelled $\editable{}$ $eighth$ $plus$ $\editable{}$ $eighth$ of the distance between his home and school.

Question 2

$Mario$ has a bucket that carries one $eighth$ of a litre of liquid, and $Joanne$ has a bucket that also carries one $eighth$ of a litre.

$Mario$ fills up his bucket with water and tips it into an empty inflatable pool $thirteen$ times. Then, $Joanne$ removes water from the pool using her bucket $three$ times.

Complete the number sentence that describes how much water is left in the pool.

The pool now has $\frac{\editable{}}{\editable{}}-\frac{\editable{}}{\editable{}}$− of a litre of water.

Question 3

$Oprah$ throws a ball and it hits the ground $ten$ $thirds$ of a metre away from her. The ball then rolls a further $two$ $thirds$ of a metre away and stops.

Select the number sentence that describes how far away the ball is from $Oprah$ .

The ball is $two$ $thirds$ $minus$ $ten$ $thirds$ of a metre away from $Oprah$ .
A
The ball is $two$ $thirds$ $plus$ $two$ $thirds$ of a metre away from $Oprah$ .
B
The ball is $ten$ $thirds$ $minus$ $two$ $thirds$ of a metre away from $Oprah$ .
C
The ball is $ten$ $thirds$ $plus$ $two$ $thirds$ of a metre away from $Oprah$ .
D

Outcomes

NA3-1

Use a range of additive and simple multiplicative strategies with whole numbers, fractions, decimals, and percentages.

Number sentences with fractions I