Letter–number codes appear in almost every GL-style verbal-reasoning paper, and they reward one thing above all: a fixed, repeatable method. In these questions a set of words is given, each paired with a number code, and your child must work out which letter maps to which digit — then use that mapping to encode a new word or decode a new number. The good news is that once a child has a reliable routine, this becomes one of the fastest, most dependable marks in the whole VR test. This guide gives you that routine, a full worked example, the exact traps that cost marks, and free practice to lock it in.
What the question actually looks like
You are shown several words alongside their codes, for example: if TAP = 125, PAT = 521 and PIT = 531, what is the code for TIP? Each letter stands for one digit, and the same letter always stands for the same digit within a question. The position of each digit in the code matches the position of its letter in the word. In a GL paper these come as multiple-choice, with answers labelled A–E on a separate OMR answer sheet, so your child selects the matching bubble rather than writing the code out. Most papers carry three to five of these questions, each worth the same mark as any other, which makes a fast, accurate method genuinely high-value preparation.
The method, step by step
The whole skill reduces to matching by position. Teach your child this exact sequence and use it every single time:
- Line the words up. Write each word above its code so letters and digits sit in the same columns.
- Find a shared letter in the same position. If two words start with the same letter and their codes start with the same digit, that letter is locked immediately.
- Lock in the certainties first. Mark down every letter you are 100% sure of before touching the doubtful ones.
- Resolve ambiguities with a third word. When two letters could each be one of two digits, look for another given word that uses just one of them.
- Build the answer letter by letter. Take the target word, swap each letter for its digit, and read the code straight off.
- Check every given word. Your mapping must make every supplied code correct, not just the easy one.
Worked example in full
Using TAP = 125, PAT = 521 and PIT = 531, find the code for TIP.
- In TAP the middle letter A gives the middle digit 2, so A = 2. Both TAP and PAT contain A in a middle-ish position and both use 2 — that confirms it.
- Compare TAP = 125 and PAT = 521. The words are the same three letters reversed at the ends: T and P have swapped. TAP starts with T and ends with P; its code starts 1 and ends 5. PAT starts with P and ends with T; its code starts 5 and ends 1. So T = 1 and P = 5.
- Now PIT = 531. We know P = 5 and T = 1, which fits the 5 and the 1. The remaining middle letter I must be the remaining digit, so I = 3.
- Assemble TIP: T = 1, I = 3, P = 5, giving TIP = 135.
- Final check: does the mapping make every given word right? TAP = 125 ✓, PAT = 521 ✓, PIT = 531 ✓. Confident answer.
Notice that the third word did all the heavy lifting for the ambiguous letter — this is why children should never guess the whole mapping from a single word.
The traps that cost marks
Almost every dropped mark on this type comes from one of a short list of avoidable errors. Walk through them with your child:
- Guessing from one word. Deducing a mapping from a single word without cross-checking against the others is the number-one mistake. Always verify against every given code.
- Ignoring position. The digit's place in the code must match the letter's place in the word. A right letter in the wrong column gives a wrong code.
- Reversing the direction. Some questions ask you to encode a word into a number; others give a number and ask for the word. Read which way round it goes.
- Repeated letters. If a word has a double letter, its code has a repeated digit in the matching spots — a useful clue, not an error.
- Rushing the transfer. On the OMR sheet, filling the wrong bubble wastes correct working. Read the letter of the answer, then find that letter on the sheet.
How this fits the wider VR test
Letter–number codes sit alongside word codes, hidden words, and letter sequences as the "code and pattern" family of GL questions. Because they share the position-matching logic, a child who masters one improves at the others. For the complete picture, our 21 VR types overview maps how each style is tested. Remember that raw marks are converted into an age-adjusted Standard Age Score (SAS, roughly 69–141 with 100 as average and around 111+ often needed for grammar entry), so every reliable mark on a fast type like this frees time and confidence for the trickier questions.
How to practise this type
Little and often wins: five questions of this type daily for a week beats fifty in one sitting. Our free verbal-reasoning worksheets are organised by exact question type, and the Arena's VR mode gives instant feedback with XP so the method becomes automatic. Once the type feels effortless, fold it back into full timed mock papers so pacing develops alongside accuracy, and use the revision hub to track which VR types still need work. If you are aiming at a specific school, the centre-specific mocks match the exact paper style your child will sit.
Frequently asked questions
How many letter–number code questions appear in an 11+ paper?
Typically three to five in a GL-style verbal-reasoning test, each worth the same single mark as any other question. They are a small share of the paper but among the most reliably winnable if the method is solid.
Is a calculator or rough working allowed?
No calculator is permitted in the 11+, and none is needed here — the digits are simply matched to letters, not calculated. Children may jot the letter-to-digit mapping in the margin of the question booklet, but final answers go on the separate answer sheet.
What year should my child start practising these?
Verbal reasoning is usually built through Year 5, with intensive timed practice in the months before the autumn test. Letter–number codes suit Year 4 and 5 pupils well because the logic is concrete; begin untimed to build the routine, then add the clock.