Interest is one of the most useful ideas in money, and it’s easier to explain than you might expect. Children don’t need the percentage first. They need to feel that waiting paid off.
Step 1: tell a story
Start with something that isn’t about banks. Our free story, The Dragon Who Paid You to Wait, has a child lending ten coins to a dragon who loves gold, and getting eleven back after the first snow. Younger children will understand the deal right away: “you get extra if you wait”.
Step 2: run the experiment
You’ll need a jar, some coins or counters, and about a week.
- Offer the deal: “If you lend me these ten coins until Sunday, I’ll give you eleven back.”
- Say what happens if they change their minds: “You can have them back early, but then you just get the ten.”
- Put the jar somewhere they can see it. Seeing it is what makes it hard, and that’s the point.
- On Sunday, pay up with some ceremony. Then offer the deal again, for a longer wait and a bigger reward.
These rates are absurdly generous, and that’s deliberate. A real-world rate on a small amount would be too small for a child to notice. You can explain later that real banks pay far less.
Step 3: answer “why would they pay me?”
A sharp child will ask this. Here’s one simple answer: “The bank borrows your money while you aren’t using it, and lends it to someone else, like a family buying a house. That family pays the bank extra for borrowing it. The bank keeps some, and gives some to you.”
The same answer works in reverse, and it’s worth saying aloud: “If you borrow money, you’re the one who pays the extra.”
Step 4: for older children, try compound interest
From about ten, try this with a calculator. Start with £100, and add 5% each year. In the first year, you earn £5. In the second, you earn 5% of £105, which is £5.25. Keep going together and watch the yearly amount creep up, and then compare it with adding a flat £5 each year. After 30 years, the difference is about £182. Most children find that surprising, and many grown-ups do too.
| After | Flat £5 a year | 5% compounded |
|---|---|---|
| 1 year | £105.00 | £105.00 |
| 10 years | £150.00 | £162.89 |
| 20 years | £200.00 | £265.33 |
| 30 years | £250.00 | £432.19 |
Let them practise
PocketQuest’s Fixed Saving does all of this with virtual coins. Children lock coins away for a term they choose, and each term shows the interest it would earn, so a longer wait visibly earns more. Coins come back automatically with a celebration when the term ends, and taking them out early means giving up the interest. You set the minimum, the term and the rate. It’s simple interest, not compound, so a good question for an older child is what would change if it were compounded.
This guide is general education for families, and it isn’t financial advice.