Thinking sheet · Brain games and puzzles

Invent a Secret Code

Make up a symbol for each letter, write a secret message and challenge a friend to crack it.

Grades
2–5
Time
about 25 minutes
Kids practice
symbols, spelling, logical thinking

What kids do

“Invent a symbol for each letter. Then write a message only a code-breaker can read!”

  1. My code key (keep it secret!)
  2. My secret message in code:
  3. Cracked by: … It took them:

How to run it

  • Fill each cell with a letter and its symbol, like A = ☆.
  • Short messages are easier to crack. Start with three words.
  • Give the code-breaker one free letter as a clue.

Talk about it

  • What made your code hard to crack?
  • Which letters show up the most?
  • Who uses codes in real life?

Take it further

Write a whole note to a friend in code.

Pairs well with

Free for home and classroom use. Print as many copies as you need.

More thinking sheets

Maze Maker thinking sheet
Brain games and puzzles

Maze Maker

Design your own maze on squared paper with one true path and lots of dead ends, then swap with a friend.

Grades 2–5 · about 30 minutes

Tic-Tac-Draw thinking sheet
Brain games and puzzles

Tic-Tac-Draw

Tic-tac-toe with doodles instead of X and O. Each player picks a tiny picture as their mark.

Grades K–5 · about 15 minutes

Dots and Boxes thinking sheet
Brain games and puzzles

Dots and Boxes

The classic pencil game: take turns joining dots, close a box to claim it and draw a tiny face inside.

Grades 1–5 · about 15 minutes

See all 400 thinking sheets

Free for teachers

Get the free Classroom Drawing Kit

12 printable pages: six step-by-step lessons, a grid activity, draw-and-write sheets and teacher notes, sent with your welcome email. After that, new classroom printables by email.

Keep creating with Kevin

New book announcements and free drawing and coloring activity pages, delivered by newsletter.