Solve Problems Using the Unitary Method

In this activity, we are using the unitary method to work out proportion problems.

You will need a calculator for this.

Recap

If a chocolate bar is 80p for 1, then we would expect to multiply 80p by the number of bars we want to buy.

If we want 3 bars then 3 x 80p = £2.40

We call this direct proportion - as one value rises so does the other!

Likewise in reverse, if we only have the price for a number of items we can divide by that number to find the price of one!

Example

A pack of 5 highlighters costs £3.50

What is the cost of one?

Method

We divide by 5 here!

3.50 ÷ 5 = £0.70 each.

We could then work out the price for any number of highlighters from there by multiplying by £0.70!

Let's try some of these!