Letter Codes: Crack the Shift (11+)

V3Letter Codes

Shift every letter by the same amount.

Letter codes slide the whole word along the alphabet — crack the shift, crack the code.

CAT in a +2 code.

CAT

+2 each letter ↓

ECV

C→E · A→C · T→V

Find the shift from a solved pair, then apply it (or reverse it) letter by letter.

Learn the 3-Step Method

1Find the shift from the example.

If DOG is written GRJ: D→G is +3. Check all letters: O→R ✓ (+3), G→J ✓ (+3).

D→G = +3

2Apply the shift to encode.

Same +3 on the new word, letter by letter, using your written alphabet.

shift each letter

3Reverse it to decode.

Coded JGNNQ with a +2 code? Go −2: J→H, G→E, N→L, N→L, Q→O → HELLO.

decode = −shift

💡 Key IdeaAlways verify the shift on every letter of the example pair — some codes shift alternate letters differently, and one check exposes it.

Worked Example

In a certain code, CAT is written ECV. How is DOG written in this code?

Crack the shift

C→E +2 · A→C +2 · T→V +2

→

Apply to DOG

D→F · O→Q · G→I

→

✓ Answer

FQI

Watch Out! Common Mistakes

Shifting the wrong direction when decoding.

decode JGNNQ (+2 code) by adding: LIPPS ✕

Reverse it! Decoding UNDOES the shift: −2 gives HELLO.

Checking only the first letter.

All letters! Some codes alternate (+2, −2, +2…). Verify the shift on every letter of the example before trusting it.

Forgetting the wrap at Z.

Y +2 → “no letter” ✕

Loop round! Y→Z→A: Y +2 = A. The alphabet is a circle in code questions.

⬇ Cheat Sheet

LETTER CODES

Find the shift from the solved example — verify on EVERY letter.
Encode: apply the shift letter by letter.
Decode: apply the shift in reverse.
Wrap past Z back to A when needed.

Example: CAT→ECV is +2, so DOG→FQI (D→F, O→Q, G→I).

📖 Continue Your Journey

✓ V1 Alphabet Skills ✓ V2 Letter Sequences V3 Letter Codes V4 Hidden Words V5 Compound Words V6 Odd One Out V7 Analogies V8 Synonym Pairs V9 Antonym Pairs V10 Missing Letters V11 Number Sequences V12 Letter-Number Codes V13 Anagram Skills V14 VR Exam Technique

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Next Lesson: V4 Hidden WordsA word hiding across the gap.

📄 Free printable: Download the Letter Codes cheat sheet (PDF) — keep it by your child's desk.

Quick summary

Work out the shift from the solved example pair.
Verify the shift on every letter — alternating codes exist.
Encode by applying the shift; decode by reversing it.
The alphabet wraps: Y + 2 = A.

Frequently asked questions

How do you crack a letter code?

Compare the example word with its coded form to find the shift (CAT→ECV is +2), verify it on each letter, then apply the same shift to the new word.

How do you decode a coded word?

Apply the shift in reverse — for a +2 code, count two letters back: JGNNQ becomes HELLO.

What if the shift runs past Z?

Continue from A — the alphabet is treated as a loop, so Y shifted +2 becomes A.