Cabudare Kids
Computers' secret code
Write your name in zeros and ones. You can even do it on paper, no internet needed.
Zeros and ones: like light switches
A computer only understands two things: off and on.
Off is written 0. On is written 1.
Each 0 or 1 is called a bit.
With 8 bits in a row, the computer writes one letter.
For example, A is 01000001.
Do it on paper
You don't need the internet. Just paper, a pencil and scissors.
- Cut out 5 paper cards.
- Draw dots: 16 on the first one, then 8, 4, 2 and 1.
- Line them up, from the 16 card to the 1 card.
- Face up is 1. Face down is 0.
- Add up the dots you can see. That number is a letter: A is 1, B is 2, and Z is 26.
- 16 dots
- 8 dots
- 4 dots
- 2 dots
- 1 dot
Example: C is 3. Leave the 2 card and the 1 card face up. You get 00011.
A secret: the computer does almost the same. It puts 010 in front, so C becomes 01000011.
Letters and their numbers
- A = 1
- B = 2
- C = 3
- D = 4
- E = 5
- F = 6
- G = 7
- H = 8
- I = 9
- J = 10
- K = 11
- L = 12
- M = 13
- N = 14
- O = 15
- P = 16
- Q = 17
- R = 18
- S = 19
- T = 20
- U = 21
- V = 22
- W = 23
- X = 24
- Y = 25
- Z = 26
Loading the game…
What about Ñ?
Spanish has a letter called Ñ. It isn't in the paper game: that alphabet goes from A to Z.
The computer can write it, with a code called UTF-8.
From A to Z it uses 8 bits per letter. Ñ needs twice as many: 16 bits.
Ñ is 11000011 10010001. Lowercase ñ is 11000011 10110001.
The same happens with accented vowels, like Á.
For grown-ups
The five-card game comes from CS Unplugged, at the University of Canterbury (New Zealand). It works without a computer.
The codes are UTF-8 (RFC 3629). From A to Z it matches ASCII: one byte per letter. Ñ and accented vowels use two bytes.
The page works out each code with the browser's own encoder. The name your child types is never stored or sent.