Computers can't read all our numbers like 1, 2, 3 … 9. Inside, they only understand two things:
0 = OFF 1 = ON
Think of tiny light switches. A computer is full of millions of them. By turning them off (0) and on (1), it can write any number.
Let's learn the code together. Tap Next to begin! 👉
Our normal numbers use ten digits (0–9). Binary uses only two: 0 and 1.
Tap the bulbs to flip them off and on. There are no other choices — that's why it's called binary (bi means two)!
In binary, the spot a switch sits in tells you its worth. Reading from the right, the values double each step: 1, 2, 4, 8 …
Tap each card to reveal its value 👇
See it? 1 → 2 → 4 → 8. Each one is double the one before. ✨
To read a binary number: turn the ON (1) values into their numbers, then add them. OFF (0) switches add nothing.
Tap the switches below and watch the total change!
When the last switch is already 1 and needs to go up, it flips back to 0 and the next one turns on — just like 9 → 10 in normal counting!
Here is a binary number. Use the values under each switch to add up the ON ones, then pick the answer.
Binary 1010 = ? (hint: 8 + 2)
What you learned:
Example: 1010 = 8 + 2 = 10
Every photo, song and game on a computer is really just lots and lots of 0s and 1s. Now you know their secret! 🌟