Money Counter

How to use it

Step 1: choose a mode.

• Make it gives you an amount, such as $3.45. Tap coins and notes to put them in the tray. Tap a piece in the tray to take it out again. When the total is right, tap Check. If you used the fewest pieces possible, you earn a ⚡ bonus. If you did not, the tool shows you how to do it with fewer.
• Count it shows a pile of money. How much is there altogether? Pick the answer from four choices, or type it. After you answer, the tool counts along from the biggest piece so you can see how the total grows.
• Change is a shopping question. You buy something and pay with a note or a coin. How much change do you get back? The tool shows the shopkeeper's way of working it out, which is to count up from the price.
• Rounding teaches the 5 cent rule. Tap any number of cents on the strip to see where it goes, try a total of your own, then answer questions about cash and card.

Step 2: choose a level. There are 4 levels, and you can start on any of them: under $1, up to $5, up to $50 and big amounts. As the levels go up, the $1 and $2 coins, then the $5, $10 and $20 notes, then the $50 and $100 notes join in.

Step 3: play a round. A round is 10 questions. A question scores a point when you get it right the first time. You earn one star for finishing a round, two stars for 7 or more points and three stars for 9 or more. The best score for each level is kept on this device.

To type an answer, write the dollars, then a dot, then the cents, like 3.45. For 85 cents, type 0.85.

The money is drawn as simple pictures, not photos. Coins are circles, and the 50c coin has 12 sides, like the real one. The 5c to 50c coins are silver and the $1 and $2 coins are gold. The $2 coin is smaller than the $1 coin, just as in real life. Notes are coloured rectangles that get a little longer as the amount goes up: purple-pink for $5, blue for $10, orange for $20, yellow for $50 and green for $100.

Why it works

Money is a way to practise place value. There are 100 cents in a dollar, so $3.45 is 345 cents. The dot in $3.45 just shows where the dollars end and the cents begin. This tool does all of its sums in whole cents, so 10c + 20c is always exactly 30c.

Counting money is skip counting. Count the 50s, then the 20s, then the 10s and the 5s. That is why the tool counts along from the biggest piece: $5, $7, $7.50, $7.70. It is easier to count big pieces first and add the small ones on top.

Making the same amount in different ways helps children see that numbers can be split up. Fifty cents can be one 50c coin, or two 20c coins and a 10c coin, or ten 5c coins. The fewest-pieces bonus makes children think about which coins are worth the most. A good tip is to start with the biggest piece that fits, and keep going. That tip works for every amount in Australian money.

Shopkeepers often give change by counting up, not by taking away. If something costs $3.60 and you pay with $5, count up: 40c makes $4, and $1 more makes $5. That is 40c + $1 = $1.40 in change. Counting up turns a tricky subtraction into easy adding.

Australia has no 1c or 2c coins. They were taken out of use in 1992, and the 5c coin became the smallest. When you pay with cash, the total is rounded to the nearest 5 cents. A last digit of 1 or 2 rounds down to 0. A 3 or 4 rounds up to 5. A 6 or 7 rounds down to 5. An 8 or 9 rounds up to 10. So $4.37 becomes $4.35, and $4.38 becomes $4.40.

The rounding is done on the whole total, not on each price. It is only for cash. If you pay by card, you pay the exact amount. These are the details that the Rounding mode asks about.

For parents and teachers

The Counter is written for Years 1 to 5. Many schools start by recognising coins and notes in Year 1, count small collections in Year 2, and give change to the nearest 5 cents in Years 3 and 4. Older children can practise bigger amounts and rounding. Ask your child's teacher which level matches their class.

Real coins make the best practice. Tip a handful onto the table and ask How much is here? Set up a pretend shop with price tags, or let your child pay and check the change at a real shop.

Some questions to ask:

• Can you make it with fewer coins?
• What would you count first? Most people start with the biggest.
• How did you work out the change? Counting up from the price is a strategy to praise.
• Why does the shop ask for $4.35 when the price tags add up to $4.37?

The items and prices in the tool are made up for practice. Real shop prices change, and shops are free to set their own.

The tool works with touch, mouse and keyboard. On a keyboard you can press 1, 2, 3 or 4 to pick an answer and Enter to move on. Every coin and note has a label for screen readers.

Progress is stored only in this browser, on this device, and is not sent anywhere. Children who share a device share the same stars, and clearing the browser's site data starts again from scratch.