Building Blocks

# Binary Decoder

Can you read a message like a computer? Computers understand binary language, which is made up of 0’s and 1’s. For a computer, different combinations of 0’s and 1’s have different meanings.

### Materials

Printable version

### What kind of key is too stubborn to open any doors?

10000

00010
01001
00101
10010
00001
01111
00000

The answer to this riddle is hidden above in binary code. Use the binary key to decode the message! First, take a look at the 5-digit code under the first line. Count how many 1's are in that piece of code. Then, find the letter that matches the code and write it on that line. Keep going until you can read the answer!

One 1
10000 = A
01000 = B
00100 = C
00010 = D
00001 = E

Two 1's
11000 = F
01100 = G
00110 = H
00011 = I
10001 = J
10010 = K
10100 = L
01010 = M
00101 = N
01001 = O

Three 1's
11100 = P
01110 = Q
00111 = R
10011 = S
11001 = T

Four 1's
11110 = U
11101 = V
11011 = W
10111 = X
01111 = Y

Five 1's
11111 = Z

No 1's
00000 = !