Lesson

How do we know if we need to multiply or divide in our problem? The words and the context they're used in tells us whether we are multiplying or dividing.

What words can you think of for division?

Idea summary

Here are some words that we may come across in multiplication and division problems:

Multiplication words | Division words |
---|---|

\text{groups of} | \text{shared among} |

\text{product} | \text{distributed between} |

\text{altogether} \\\text{quotient} | \text{multiplied by} \\\text{shared equally} |

\text{product} | \text{per} |

This year there are 2627 registered self-driving cars in the world. By the same time next year there are expected to be 9 times as many self-driving cars.

a

Which number sentence correctly describes to total number of self-driving cars registered by next year?

A

9 + 2627

B

9 \times 2627

C

9 \div 2627

D

2627 \div 9

Worked Solution

b

Find the total number of self-driving cars registered by next year.

Worked Solution

Idea summary

If a story problem uses the word "times" then we need to multiply.

A real estate agency has portfolio of 6 properties that it manages. The total value of the properties is \$3\,518\,400.

If each property is valued equally, what is the cost of one of the properties in the portfolio?

Worked Solution

Idea summary

Sometimes there may be pieces of information that are not relevant to our problem. How do we know which things we need? The best thing to do is to highlight the keywords, and then think about what they are suggesting, these are like the clues to the puzzle.

Identifying the clues helps us work out how to write out our number problem. We can also look for pieces of information that may not be useful, and ignore those.

Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers and make estimates for these computations