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.(+)×=
- 2.3−2+=CODE 1
- 3.−=
- 4.+=CODE 2
- 5.×−=
- 6.×−=CODE 3
- 7.×(−)=
- 8.3−2+=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: cross = 1 · hexagon = -5 (hidden) · lightning bolt = 8 · circle = -4 (hidden) · heart = 7 · triangle = -8 (hidden)
Every symbol is a whole number from -9 to 20 (some are negative!).
Vault code: 7911