A secret message is just normal words wearing a disguise 🕵️. Your job is to find the rule of the disguise. Once you know the rule, you can write secret messages of your own!
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Almost every coding question needs this. Each letter has a position number. Learn it once and you will never be stuck again.
You only need to remember five letters. Every fifth letter spells the funny word E-J-O-T-Y. Then just hop forwards or backwards.
E
5
J
10
O
15
T
20
Y
25
Example: what is the position of R? The nearest anchor is T = 20. R is two letters before T, so R = 20 − 2 = 18. Done in two seconds!
🔄 Counting backwards (from Z)
Sometimes a question asks for the position from the end. There is a simple formula:
position from the end = 27 − position from the start
Example: D is 4th from the start, so it is 27 − 4 = 23rd from the end. Check: Z is 1st from the end and 26 from the start → 27 − 26 = 1 ✅
In a shift code, every letter takes the same number of steps along the alphabet.
C A T → D B U
C→D, A→B, T→U — every letter moved 1 step forward.
How to find the shift: compare just the first letter of both words. Then check with a second letter to be sure.
Cover the steps with your hand and try first!
Watch the edges! If you go past Z, start again at A. So Y + 2 = A, and Z + 1 = A. Going backwards past A, you land on Z: A − 1 = Z. Think of the alphabet as a circle 🔄.
In this code every letter moves 1 step forward. Match each code to its real word.
Here letters turn into numbers. There are three favourite tricks — check them in this order.
Which trick is it? If the code is as long as the word, each letter became a number. If the code is one small number, they were probably added together.
In these questions the maths signs swap places! For example: "If + means ×, then 4 + 5 = ?"
Method: rewrite the sum with the real signs first, then solve it. Never try to do both at once — that is how mistakes happen.
4 + 5 → 4 × 5 = 20
📐 After you swap, solve in the right order
Do × and ÷ first, then + and −, working from left to right.
If × means + and + means ×, then 3 × 4 + 2 = ?
Step 1 — swap the signs: 3 + 4 × 2
Step 2 — do × first: 4 × 2 = 8
Step 3 — now add: 3 + 8 = 11
12 IMO-style questions. Write the alphabet on your rough sheet before you start — it helps! 🍀
