Equivalent amounts | Year 3

01 / LEARN

The idea, step by step

Equivalent amounts have the same value. Two 50-cent coins and one 1-dollar coin are equivalent because both total 100 cents.

To check equivalence, add each collection separately using the same unit. If both totals match, either collection could pay that exact amount.

A collection with more coins is not always worth more. Five 10-cent coins total 50 cents, while one 2-dollar coin totals 200 cents.

You may be asked for any way to make an amount, or for a way using a particular number of coins. Check both the total and any condition.

The collection with more coins must have greater value.

Instead: Add the values. One high-value coin can be worth more than several low-value coins.

02 / WORKED EXAMPLES

Example 1

Show 1 dollar using 50-cent coins, then using 20-cent coins.

Two 50-cent coins or five 20-cent coins.

Example 2

Which has more value: three 20-cent coins or one 50-cent coin?

Three 20-cent coins, by 10 cents.

Are 50c + 20c + 20c + 10c and 1 dollar equivalent?

Show answer

Yes.

$50 + 20 + 20 + 10 = 100$ cents, and 100 cents make 1 dollar.

03 / WORKSHEET

6 questions · Work at your own pace.

Read the questions online

Read the worked solutions

How many 20-cent coins make 1 dollar?
$5 \times 20 = 100$ cents.
5 coins.
Give two different coin collections worth 40 cents.
$20 + 20 = 40$ and $10 + 10 + 10 + 10 = 40$ . Other valid collections are acceptable.
For example, two 20-cent coins; or four 10-cent coins.
Find the total: 1 dollar + 50 cents + 20 cents.
$100 + 50 + 20 = 170$ cents.
1 dollar 70 cents.
Which is worth more: four 10-cent coins or one 50-cent coin?
Four 10-cent coins total 40 cents; $50 - 40 = 10$ .
The 50-cent coin, by 10 cents.
Make exactly 1 dollar using exactly 2 Australian coins.
$50 + 50 = 100$ cents, using 2 coins.
Two 50-cent coins.
A child swaps one 2-dollar coin for five 20-cent coins. Is the value equal?
$5 \times 20 = 100$ cents, but 2 dollars are 200 cents.
No. Five 20-cent coins total only 1 dollar.

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Modelling purchases

Curriculum reference & lesson scope

Australian Curriculum v9 and SA Curriculum Mathematics

Dollars/cents; equivalent amounts; modelling purchases; needs/wants; class enterprise and others' wellbeing.