CRACK THE CODE · GRADE 5
The Coral Reef Cryptogram
Solve the sea-shape equations using your knowledge of multi-digit division to find the four-digit code that opens the mermaid queen's pearl safe.
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.××=
- 2.3+2=CODE 1
- 3.(+)×=
- 4.(+)×=CODE 2
- 5.××=
- 6.3+2=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 mermaid queens pearl.
Show answer key (for grown-ups)
Key: heart = 6 (hidden) · circle = 8 · ring = 14 · pentagon = 17 · cross = 12 (hidden) · hexagon = 20 (hidden)
Every symbol is a whole number from 1 to 20.
Vault code: 2061