Roman Numerals

Two thousand years ago, every number was written with letters. You still see them on clocks, films, and old buildings.

Scene 1

Seven letters, all the numbers ✍️

The Romans had only seven letters for all their numbers. No zero. No "1234". Just these:

100

500

1,000

You make any number by adding these up: VIII = 5 + 1 + 1 + 1 = 8. XXVII = 10 + 10 + 5 + 1 + 1 = 27.

Scene 2

The clever trick: subtraction 🧠

If you put a smaller letter before a bigger one, you subtract. So:

• IV means "one before five" = 4 (not "VIIII")
• IX means "one before ten" = 9
• XL means "ten before fifty" = 40
• XC means "ten before hundred" = 90

That's why the Roman shorthand is shorter than you'd think — IV is two letters instead of four.

Scene 3 · Try it

Type a number, see the Roman 🔢

Try your age, the year, your birthday number…

The Big Idea

Why we left them behind ⏰

Roman numerals look beautiful — and you'll still see them on clock faces, film credits, popes' names, Olympic Games. But try doing 47 × 89 with them. Almost impossible.

That's why the world switched to Indian-Arabic numerals (the 0–9 we use today). They have a zero, they line up nicely, and you can do maths in columns. Roman numerals were left behind for the same reason horse-drawn carts were — newer, faster ideas came along.