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CRACK THE CODE · GRADE 1

Captain Redbeard's Secret Treasure Code

Find the hidden number for each pirate symbol to unlock the iron treasure chest.

Each shape stands for a number. 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.

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The key

=4
=5
=1
=6

Every symbol is a whole number from 1 to 9.

Crack these

  1. 1.+7=
  2. 2.+=CODE 1
  3. 3.+=
  4. 4.19−=CODE 2
  5. 5.+4=
  6. 6.++=CODE 3
  7. 7.−=
  8. 8.19−=CODE 4
  9. 9.+?=5Which shape?
  10. 10.+?=9Which shape?

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 iron-bound treasure chest.

Show answer key (for grown-ups)

Key: moon = 4 · pentagon = 5 · ring = 1 · square = 6

Every symbol is a whole number from 1 to 9.

1.ring + 78
2.square + moon10
3.pentagon + ring6
4.19 - ring18
5.moon + 48
6.ring + square + moon11
7.moon - ring3
8.19 - pentagon14
9.ring + ? = 5moon
10.moon + ? = 9pentagon

Vault code: 0814

About Crack the Code

Crack the Code is early algebra without the letters: a key maps shapes to numbers, and the kid substitutes, computes, and — from grade 3 up — deduces hidden values from shape equations before they can solve anything. Grade 1 practices addition and subtraction within 20, and finding a missing shape. Every sheet has exactly one right key and one right code.

It's one of three things Math Crackers makes, free and printable, personalized to what your kid is into: a full math whodunit, a Lab Work sheet of multi-step word problems, or a Crack the Code sheet like this one. Browse free printable worksheets by grade, skill, and theme.

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