Math CrackersMake a mystery

CRACK THE CODE · GRADE 2

Dinosaur Dig Code Breaker

Use your math skills to figure out what each dinosaur symbol stands for and unlock the fossil storage 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.

Print / download PDFMake another

The key

=1
=5
=7
=9
=6

Every symbol is a whole number from 1 to 10. A number in front of a shape means multiply: 2 stars = 2 x star.

Crack these

  1. 1.3−=
  2. 2.3−=CODE 1
  3. 3.2=
  4. 4.2+2=CODE 2
  5. 5.+=
  6. 6.++=CODE 3
  7. 7.3=
  8. 8.−=CODE 4
  9. 9.?+=7Which shape?
  10. 10.+?=10Which 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 jurassic fossil storage.

Show answer key (for grown-ups)

Key: lightning bolt = 1 · cross = 5 · square = 7 · hexagon = 9 · heart = 6

Every symbol is a whole number from 1 to 10.

1.3 x heart - hexagon9
2.3 x hexagon - cross22
3.2 x square14
4.2 x square + 2 x cross24
5.square + hexagon16
6.cross + hexagon + heart20
7.3 x cross15
8.hexagon - lightning bolt8
9.? + lightning bolt = 7heart
10.hexagon + ? = 10lightning bolt

Vault code: 2408

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 2 practices addition, subtraction, and multiplying by 2 and 3. 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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