Two letters, two jobs
The Short Answer
A horizontal code question shows a row of figures, each labelled with two code letters, and asks for the code of one more figure. Nobody tells you what the letters mean — working that out is the question. The two letters always describe different features, so they are solved one at a time, and each rule is proved by checking it against a figure that does not carry that letter.
Nobody tells you what the letters mean
That is not an oversight. Working out what they mean is the question.
Three or four boxes in a row, each with a picture inside, and each with two code letters — one in the top corner, one in the bottom. Then one more box, on its own, with both corners empty.
And here is the fact the whole method rests on: the top letter and the bottom letter do different jobs. The top one might be about the shape; the bottom one about how many there are, or the shading. They are never about the same thing.
Two Letters, Two Jobs
Put a finger over the bottom letters. You are only working on the top row now.
Find two boxes that share a top letter, and ask what those two pictures have in common.
Check it against a box with a different top letter. That box must not have the thing you just found. If it does, your idea is wrong — and you have saved yourself a mark rather than lost one.
Then move your finger and do the bottom row the same way. Read the new picture, and write its code.
What a letter can stand for
The shape. How many there are. The shading — white, grey, black, striped. The size. Whether the outline is solid or dashed. Which way something points. Even where a tiny dot sits in the box.
The test to use: can you point at it?
If you cannot put your finger on the difference between two pictures, then that is not the rule, and you are about to talk yourself into a wrong answer.
Where do pupils lose marks?
Writing the two letters the wrong way round after working both out correctly. Entirely avoidable, and it happens under time pressure. Say the code aloud in order before choosing.
Deciding what a letter means from a single box. That works about half the time, which is exactly often enough to feel like a method.
Never checking against a box without the letter, so an idea never becomes a rule.
Choosing an option because the first letter matches. Several options will share the first letter — that is deliberate. Check both.
How can we practise this at home?
Make codes for anything. Line up five objects from a drawer and give each one a two-letter code — the first letter for what it is made of, the second for its colour. Then add a sixth object and ask for its code.
Being the person who writes the code teaches the structure faster than solving them does, because you have to decide what each letter position is for before you can label anything.
Free: a Non-Verbal Reasoning workbook
Questions across the Non-Verbal Reasoning question types, with the method printed at the top and full answers at the back. One workbook for the whole strand, not a sheet per question type.
Frequently Asked Questions
What is the method you teach?
Two Letters, Two Jobs. Put a finger over the bottom letters so you are only working on the top row. Find two boxes that share a top letter and ask what those two pictures have in common. Then check the idea against a box with a different top letter — that box must not have the thing you just found. Then do the same for the bottom row, and read the new figure.
Why check against a box with a different letter?
Because that is what turns an idea into a rule. If two figures share the letter M and both have a triangle, M might mean triangle — or the triangle might be in all of them and be nothing to do with M. Checking a non-M figure settles it: if that one also has a triangle, the idea is dead, and you have saved yourself a mark rather than lost one.
What can a code letter stand for?
The shape. How many there are. The shading — white, grey, black, striped. The size. Whether the outline is solid or dashed. Which way something points. Even where a small dot sits in the box. The useful test is whether you can point at it: if you cannot put a finger on the difference between two pictures, that is not the rule and you are about to talk yourself into a wrong answer.
What is the most avoidable mistake here?
Working out both letters correctly and then writing them the wrong way round. It is painful, it is common under time pressure, and it costs a mark that was entirely earned. Saying the code aloud in order — top first, then bottom — before choosing an option prevents it.
Sources
- GL Assessment — 11+ familiarisation materials and question type descriptions Published 2025.
- Clever Clogs Academy — our own Year 4 and Year 5 lesson records, Winslow Published September 2025 to July 2026.
We are not affiliated with, endorsed by or connected to GL Assessment or Buckinghamshire Council. Test arrangements change; always check the council's own pages for the current year's dates.
We Teach This Method Every Week in Winslow
Groups of no more than six pupils with two qualified teachers, in person or online. Come and see a session before you decide.