Lesson 4 · Computers

Binary: How Computers Count

We have 10 fingers, so we count in 10s. Computers have only 2 "fingers" — on and off. Let's count their way.

Scene 1

The light bulb trick 💡

Imagine a row of 8 light bulbs. Each one is worth a special number: 1, 2, 4, 8, 16, 32, 64, 128. Each bulb is exactly double the one before it. To make any number, just turn on the right bulbs and add them up.

For example, to make 5, turn on the 4-bulb and the 1-bulb. 4 + 1 = 5. To make 10, turn on the 8-bulb and the 2-bulb. 8 + 2 = 10. Try it!

Scene 2 · Try it

Tap the bulbs. Add them up. ✨

00000000

In binary

Challenge

Can you make 13?

Tap bulbs to add up to the target.

Scene 3

This is exactly how computers think 💻

Inside every computer, phone, and game console, there are millions of tiny switches — just like our bulbs. Each one is either on (1) or off (0). By flipping them in clever patterns, computers can store numbers, words, pictures, and entire movies.

Your name "VI AN" in computer language looks like this: 01010110 01001001 00100000 01000001 01001110 — five sets of 8 bulbs, on and off.

The Big Idea

Two symbols, infinite possibilities 🤯

0 1 0 0 1 1 0 1

You only need two symbols — 0 and 1 — to count to any number, write any word, paint any picture, or play any song. Every YouTube video, every photo, every text message is just a long pattern of bulbs turning on and off.

That's the entire secret of how computers work. You just learned it.