You may have already looked at representing and comparing fractions as areas. You may also 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.

Now watch this video to look at representing fractions with 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 to help understand the mathematics in the story.

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

Worked Examples

Question 1

$Hannah$ had climbed $one$ $seventh$ of the ladder to the roof when she realised she'd forgotten her $phone$ , so went back down to get it.

Complete the number sentence that describes how far in total $Hannah$ has climbed once she has returned to the bottom of the ladder.

$Hannah$ has climbed $\editable{}$ $seventh$ $plus$ $\editable{}$ $seventh$ of the length of the ladder.

Question 2

Which of the following scenarios fits the number sentence:

" $Bob$ is now $15$15 $nineteenth$ s $minus$ $7$7 $nineteenth$ s of a kilometre away from where he started."

$Bob$ walked $fifteen$ $nineteenth$ s of a kilometre, rested and then walked $seven$ $nineteenth$ s of a kilometre back.
A
$Bob$ walked $fifteen$ $nineteenth$ s of a kilometre, rested and then walked $seven$ $nineteenth$ s of a kilometre further.
B
$Bob$ walked $seven$ $nineteenth$ s of a kilometre, rested and then walked $fifteen$ $nineteenth$ s of a kilometre back.
C
$Bob$ walked $fifteen$ $nineteenth$ s of a kilometre, rested and then walked $one$ $nineteenth$ of a kilometre back.
D

Question 3

$Lachlan$ throws a ball and it hits the ground $four$ $elevenths$ of a metre away from him. The ball then rolls a further $twelve$ $elevenths$ of a metre away and stops.

Complete the number sentence that describes how far away the ball is from $Lachlan$ .

The ball is $\frac{\editable{}}{\editable{}}+\frac{\editable{}}{\editable{}}$+ of a metre away from $Lachlan$ .

Outcomes

NA3-1

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

Number sentences with fractions II