CRACK THE CODE · GRADE 3
Roanoke Island Secret Cipher
Use math to find the missing numerical values of colonial symbols and unlock the hidden passage to the lost settlement.
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 12. 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
- 1.10+=
- 2.×+=CODE 1
- 3.×+=
- 4.×−=CODE 2
- 5.10+=
- 6.5−=CODE 3
- 7.3−=
- 8.++=CODE 4
- 9.3−=
- 10.++=
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 governor whites iron-bound.
Show answer key (for grown-ups)
Key: star = 7 · cross = 3 (hidden) · hexagon = 8 · moon = 4 · circle = 9 · diamond = 12 (hidden)
Every symbol is a whole number from 1 to 12.
Vault code: 2980