CRACK THE CODE · GRADE 7
Crack the Vault Code
Someone locked the vault with a 4-digit code. Work out what each shape is worth and crack it.
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 -9 to 20 (some are negative!). A number in front of a shape means multiply: 2 stars = 2 x star. A small 2 after a shape means square it: star^2 = star 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.(+)×=CODE 1
- 3.2+=
- 4.3−2+=CODE 2
- 5.×−=
- 6.+=CODE 3
- 7.−−=
- 8.−=CODE 4
- 9.+×=
- 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 vault.
Show answer key (for grown-ups)
Key: diamond = 12 · heart = -7 · star = -6 (hidden) · pentagon = 10 (hidden) · ring = 13 (hidden) · cross = 6
Every symbol is a whole number from -9 to 20 (some are negative!).
Vault code: 6001