NZ Level 3
topic badge
Number sentences with fractions I
Lesson

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.

  1. 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.

  1. 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.

  1. 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

    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.

What is Mathspace

About Mathspace