2. Addition and subtraction

Lesson

Sometimes we have written problems, where we need to know how to read and write numbers .

Write the number that is ten more than sixty one thousand, five hundred and ninety seven.

Worked Solution

Idea summary

We can use place value tables to write numbers as numerals, and to add numbers.

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.

Gwen has 37 raffle tickets to sell. She is able to sell 4 tickets to Luke and 9 tickets to Kate. If James now wants to buy all of her remaining tickets, how many are left for him to buy?

Worked Solution

Idea summary

Key words in a word problem help us know which operations we need to use to solve the problem.

In this story problem, we find out how to write out the number problem, with both addition and subtraction.

There were 13 flowers in Pauline’s garden. 2 more flowers grew, then Pauline picked 8 flowers to put in a vase.

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

A

13+2+8

B

13-2+8

C

13+2-8

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

generalises properties of odd and even numbers, generates number patterns, and completes simple number sentences by calculating missing values