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CRACK THE CODE · GRADE 8

Astrophysics Terminal Decryption

Solve the system of equations represented by astronomical symbols to calculate the correct frequency and unlock the emergency distress transmitter.

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

?=
?=
=18
=2
?=
?=

Every symbol is a whole number from 1 to 30. A number in front of a shape means multiply: 2 stars = 2 x star. A small 2 after a shape means square it: star^2 = star x star. sqrt(shape) is the square root of that shape's value.

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.

+3=106
32=21
×=79
×=542

Crack these

  1. 1.22+=
  2. 2.√()+=CODE 1
  3. 3.2=
  4. 4.2+2=CODE 2
  5. 5.√()×=
  6. 6.2=CODE 3
  7. 7.(+)2=
  8. 8.(+)2=CODE 4
  9. 9.2+2=
  10. 10.22+=

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 emergency distress transmitter.

Show answer key (for grown-ups)

Key: heart = 27 (hidden) · hexagon = 25 (hidden) · moon = 18 · pentagon = 2 · square = 21 (hidden) · star = 3 (hidden)

Every symbol is a whole number from 1 to 30.

1.2 x square^2 + pentagon884
2.sqrt(hexagon) + star8
3.moon^2 - heart297
4.heart^2 + square^21170
5.sqrt(hexagon) x moon90
6.hexagon^2 - pentagon623
7.(hexagon + pentagon)^2729
8.(hexagon + moon)^21849
9.hexagon^2 + moon^2949
10.2 x pentagon^2 + moon26

Vault code: 8039

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 8 practices systems of two equations, squares, and square roots. Every sheet has exactly one right key and one right code.

It's one of three things Math Mysteries makes, free and printable, personalized to what your kid is into: a full math mystery 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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