Caesar cipher: algorithm efficiency: secret code puzzle for Grade 12, page 1 preview

Secret code puzzle · Coding

Caesar cipher: algorithm efficiency · Grade 12

Crack a Caesar cipher: work out how far the alphabet was shifted, then decode facts about algorithm efficiency. Practices pattern spotting and logical reasoning.

Grade 12 · ages 17 to 18
Hard
5 to 10 minutes
1 page
Free

The answer key is a separate page for grown-ups. Sign in to download it.

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What the sheet says

Directions: Each letter has been moved along the alphabet by the same number of places. Work out the shift, fill in the key, then decode.

Code key: top row = code letter, bottom row = real letter

What your child practices

Your child practices pattern spotting and logical reasoning.

Grades and ages: Grade 12, ages 17 to 18
Time: About 5 to 10 minutes
Subject: Coding
Level: Hard for Grade 12
Answer key: Yes, for grown-ups who sign in
Printing: 1 page, US Letter or A4, low-ink option
Updated: October 15, 2026

How to use it

Read the rules at the top together and try the first step side by side. Use a pencil so mistakes rub out easily, and check every answer at the end. It is one of the harder sheets for Grade 12, best once the basics of the topic are secure.

An answer key comes with it as a separate page that grown-ups download after signing in.

Tip for grown-ups: Start with the shortest coded words; one- and two-letter words crack the code fastest.

Done on paper? A grown-up can record it on the child's page in PlayOwl; downloading alone doesn't count as finished.