Right across, wrong down: matrix questions

What a matrix question asks

Nine squares, one missing, five options.

The useful way to think about it is this: a grid is a series you can read in two directions. Everything your child knows about series still applies — it simply applies twice.

At 11+ level, expect two patterns, and sometimes three.

The G.R.I.D. method

Four letters, and they spell the question type, so it is hard to forget.

G — Go along a complete row and identify what changes. R — Run that change into the row containing the gap. I — Inspect the columns for a second, independent pattern. D — Decide, then verify the answer against its row and its column before committing.

The I is where the marks are. A pupil who only reads rows is systematically wrong on the harder half of the section, and consistently so — which is a much easier problem to fix than a vague one.

The five patterns that come up

Across and down — one attribute changes along the rows, a different one down the columns. Once each way — each shape, shading or position appears exactly once in every row and column. Rotation — the figure turns by a fixed amount along each row. Size and number — growing, shrinking, one more each time. Combinations — two or three of the above at once.

Elimination beats pattern-spotting

This is the best technique on the Non-Verbal Reasoning paper, and it is worth teaching before anything clever.

When each figure appears once in each row and once in each column, do not hunt for a rule. Cross things off instead.

1. List what the row already has. Cross those off.
2. List what the column already has. Cross those off.
3. Whatever is left is the answer — and there will be exactly one thing left.

It works even when the pattern is invisible, which is exactly when a child needs it most. Under time pressure it is the most reliable thing they can do.

Where do pupils lose marks?

Solving the rows and stopping. The biggest one, by a distance. One option is deliberately built to be right across and wrong down.

Working from a row that contains the gap, which can support more than one story.

Missing a third pattern. At the top of the range, shape, shading and size can all be doing something different. Sweep the square once for each attribute before choosing.

Forgetting elimination on 'once each way' grids, and losing thirty seconds hunting for a movement rule that is not there.

How can we practise this at home?

Draw them. A three-by-three grid with a shape that rotates along the rows and changes shading down the columns takes two minutes to draw and is a real question.

Then swap over: let your child set one for you, and get one wrong on purpose in the row-right, column-wrong way. Being the person who spots that error teaches it better than being told about it.

The question worth asking every time, before the answer is given: "and does it work going down?"