CRACK THE CODE · GRADE 4
The Whispering Library Cipher
Crack the numerical values of the ancient symbols to open the locked compartment holding the legendary golden book.
Each shape stands for a number. Work out the missing ones first, then solve the shape equations and read off the 4-digit code. Do it here or print the sheet — the answer key comes with it.
The key
Every symbol is a whole number from 1 to 15. A number in front of a shape means multiply: 2 stars = 2 x star.
Find the missing values
Some shapes in the key are missing. Use these equations to work them out, then write them into the key. Take them in order.
Crack these
- 1.×=
- 2.3+2=CODE 1
- 3.×=
- 4.×−=CODE 2
- 5.10−=
- 6.(+)×=CODE 3
- 7.×−=
- 8.(+)×=CODE 4
- 9.100+=
- 10.3+2=
The vault code
Take the ones digit of your answers to problems 2, 4, 6, 8 (the ones tagged CODE 1–4), in that order. That opens the brass-bound library chest.
Show answer key (for grown-ups)
Key: ring = 13 (hidden) · pentagon = 11 · cross = 5 · triangle = 6 (hidden) · diamond = 7 (hidden) · hexagon = 4
Every symbol is a whole number from 1 to 15.
Vault code: 9824