CRACK THE CODE · GRADE 5
The Lost Chapter Vault
Determine the numeric value of each library symbol to crack the four-digit code that opens the protected archive cabinet.
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 20. 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.÷2+=CODE 1
- 3.×−=
- 4.×(−)=CODE 2
- 5.×(−)=
- 6.10−=CODE 3
- 7.10−=
- 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 heavy oak cabinet.
Show answer key (for grown-ups)
Key: square = 20 (hidden) · lightning bolt = 10 (hidden) · diamond = 4 (hidden) · hexagon = 18 · star = 14 · moon = 8
Every symbol is a whole number from 1 to 20.
Vault code: 9000