3.3 Multiplication and Division

In the previous section, we noted that the processes of addition and subtraction can be described in several different ways in questions and problems. Let’s begin by doing the same with multiplication and division.

Here are some examples of different words that are used for multiplication:

  • 5 times 6.
  • 3 lots of 20.
  • The product of 6 and 7.
  • You might see on an automated teller machine: “Please enter a multiple of $20.”

All the words in bold are again “trigger” words telling us we need to multiply.

Can you suggest some practical situations when this operation is used? Here are some we came up with:

  • Cooking, such as doubling the ingredients needed for a recipe or cutting them in half.
  • To work out the cost of multiple items—eight books at $4.99 each, say.
  • Calculating your daily income based on your hourly pay rate.

Now let’s take a look at division.  Here are some examples of different words and phrases that are used for division:

  • How many times does 8 go into 72?
  • How can we share 72 items equally among eight people?
  • How many lots of  five are there in 20?

Can you suggest some practical situations when this operation is used?  Here are some we came up with:

  • Dividing a bill equally among a given number of people.
  • Sharing slices of pizza equally among friends.
  • Working out how many measures of liquid there are in a container.

Ask your friends and family how they use multiplication or division.

3.2 Time, Addition, and Subtraction

3.3.1 Multiplication and Division Notation