Coding-Decoding Questions for Class 4 with Answers

Coding-decoding questions give a word and its secret code, then ask the child to code a new word the same way. "If CAT is written as DBU, how is DOG written?" The child has to find the rule (each letter moves one step forward) and apply it. It's one of the most common Olympiad reasoning question types from Class 3 upwards.

What your child should know

• Compare each letter of the word with its code to find the rule.
• Common rules: move each letter forward or back, reverse the word, or replace letters with numbers.
• Write the alphabet with position numbers (A=1 … Z=26) as a quick reference.
• Check your rule on every letter before applying it.

5 Coding-decoding questions with answers

Read each question with your child and let them answer before you open Show answer.

Q1. If PEN is coded as QFO, how is BOOK coded?

A) CPPL
B) CPPM
C) BPPM
D) CPOL

Show answer

Answer: A) CPPL

Each letter shifts forward by one: B→C, O→P, O→P, K→L.

Q2. If CAT is coded as DBU, how is DOG coded?

A) EPH
B) EPI
C) EOH
D) DPG

Show answer

Answer: A) EPH

Each letter is shifted one forward: D→E, O→P, G→H.

Q3. If CAR is coded as R A C, how is BUS coded?

A) S U B
B) B U S
C) S B U
D) U S B

Show answer

Answer: A) S U B

The order of letters is reversed.

Q4. If BOX is coded as YPC, how is FOX coded?

A) YPG
B) YQG
C) YOG
D) XPG

Show answer

Answer: A) YPG

Each letter shifts forward by one: F→G, O→P, X→Y (reverse order).

Q5. If 123 is coded as 234, how is 456 coded?

A) 567
B) 568
C) 556
D) 667

Show answer

Answer: A) 567

Each digit increases by 1.

How to practise coding-decoding at home

• Send your child secret coded notes, like "IFMMP" for HELLO.
• Let them invent a code and challenge you to crack it.
• Practise saying the alphabet backwards. It speeds up "one step back" codes.

Keep going

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