Lesson

Using a number line is helpful to solve addition or subtraction problems, and helps when we have more than one part to our problem.

Use the number line to help you find the value of 43+12.

Worked Solution

Idea summary

To add numbers on the number line, find the bigger number on the number line then jump to the right by the number we are adding.

Sometimes we need to read written or story problems, and work out what we need to solve. In this video, we have to find out what our problem is, then solve it.

There were 14 flowers in Eileen’s garden. 3 more flowers grew, then Eileen picked 6 flowers to put in a vase.

a

Which number sentence matches the word problem for the number of flowers left in the garden?

A

14-3+6

B

14+3-6

Worked Solution

b

How many flowers are left in the garden?

Worked Solution

Idea summary

When we have a word problem, we need to think about the story and use the keywords to work out which operators to use. Some words that we may find in a story could be:

addition | subtraction |
---|---|

more | less |

add | subtract |

give to | take away |

plus | minus |

uses mental and written strategies for addition and subtraction involving two-, three-, four and five-digit numbers