Math CrackersMake a mystery

CRACK THE CODE · GRADE 2

Mission Control Space Code

Solve the astronaut and rocket math equations to reveal the numbers that unlock the moon rover.

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

=1
=5
=3
=9
=4

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. 1.2=
  2. 2.++=CODE 1
  3. 3.+=
  4. 4.+−=CODE 2
  5. 5.3=
  6. 6.2+2=CODE 3
  7. 7.3−=
  8. 8.2+2=CODE 4
  9. 9.?+=7Which shape?
  10. 10.?+=6Which 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 moon rover supply.

Show answer key (for grown-ups)

Key: ring = 1 · lightning bolt = 5 · circle = 3 · hexagon = 9 · star = 4

Every symbol is a whole number from 1 to 10.

1.2 x circle6
2.lightning bolt + circle + ring9
3.star + lightning bolt9
4.lightning bolt + star - hexagon0
5.3 x circle9
6.2 x ring + 2 x star10
7.3 x star - hexagon3
8.2 x lightning bolt + 2 x star18
9.? + circle = 7star
10.? + lightning bolt = 6ring

Vault code: 9008

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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