Growing It
How money can quietly make more money all by itself — and why starting early matters more than starting big.
Hatchlings · Ages 5–6
Your money can grow all by itself — even while you're asleep!
When you keep your money somewhere safe, like a bank, something lovely happens. The bank looks after it for you. And every so often, it says thank you by adding a tiny bit more.
You don't have to do anything at all. You don't have to wait for a birthday, or help with the washing up. Your money just... grows, quietly, while you're busy playing.
It really is only a tiny bit each time. But the tiny bits keep coming, and every single one of them stays in your nest. So the longer you leave your money alone, the more it grows.
Try this: Line up ten pennies. Now add one more and say "thank you!" That's the bank saying thanks for letting it look after your money.
Fledglings · Ages 7–8
Money in a bank doesn't just sit there — it slowly makes more money. That's called interest.
Here's how it works. When you keep money in a savings account, the bank looks after it, and pays you a small thank-you for letting it. That thank-you money is called interest, and it arrives in your account without you lifting a finger.
Now here's the clever part — and it might be the best trick on this whole website. The next time the bank says thank you, it doesn't just say thank you for your original money. It says thank you for your interest as well, because that's your money now too.
So your money earns money. Then that money earns money. It's like rolling a snowball down a hill: it starts small, but the bigger it gets the more snow it picks up, and the faster it grows. We call this the Snowball, and you'll bump into it all over this site.
Money in a bank grows gently and safely. There's another way people grow money that can grow faster — though it can go down as well as up. That's the next zone, Own a Slice.
Try this: Imagine a very generous pretend bank that adds £10 for every £100 you keep with it, once a year. You start with £100, so after a year you have £110. Now work out year two — remember, this time the bank says thank you for the whole £110, not just your first £100. How much do you end up with?
High Flyers · Ages 9–10
Interest is money your money earns. Compound interest is money your interest earns — and given enough time it does something almost unbelievable.
Start with the simple part. Put money in a savings account and the bank pays you interest: a small amount, usually once a year, for letting it look after your money. Imagine a bank paying 5% — that means for every £100 you've saved, you get £5 at the end of the year.
If that were the whole story, £100 would become £105, then £110, then £115. Steady, but not thrilling.
But it isn't the whole story. In year two, the bank pays interest on your £105 — not your original £100. So you earn slightly more. In year three it pays on £110.25. Your interest starts earning interest of its own. That's compound interest, and it's why grown-ups get strangely excited about savings accounts.
Here's how odd it can get. Imagine a magic penny that doubles every single day. Day one, 1p. Day two, 2p. Day three, 4p. It feels pathetic for ages — after a fortnight you'd have about £82. But keep going, and by day 30 that single penny has become £5,368,709.12.
Nothing in real life doubles that fast. But the shape of it is real: growth that feeds on itself crawls at first and then climbs almost vertically. Which leads somewhere genuinely useful — when you start matters more than how much you start with. A small amount left alone for a very long time can beat a large amount left alone for a short one.
Try this: Work out 5% of £100 and add it on. Now do the same to your new total. Keep going for ten rounds — use a calculator. How much did you gain in round one, and how much in round ten? That growing gap is compounding.
What's next
The next zone in Money World is Own a Slice — what it really means to own a tiny piece of a company, and why patient owners tend to do well.
Or go back to Saving, where all of this started.