Most sequence and pattern questions are built from a small set of rules. Once you know the rules and the order to check them in, questions that looked arbitrary become quick. This guide covers both kinds you will meet: number sequences and visual matrix puzzles.
The common mistake is staring at a sequence hoping the rule announces itself. That works on easy items and fails on everything else. What works is a fixed order of checks, applied fast, so you spend your thinking on the one candidate rule that survives.
The order below is deliberate. It puts the most common rules first, and each step takes only a few seconds.
Subtract each term from the next. This single move solves a large share of sequences outright.
3, 7, 11, 15, ?
Differences: 4, 4, 4. Constant, so add 4. Answer: 19.
If the differences are not constant, look at them as a sequence in their own right and take differences again. A constant second difference means the rule is quadratic.
2, 3, 5, 9, 17, ?
Differences: 1, 2, 4, 8. Those are doubling, so the next difference is 16. Answer: 33.
If differences grow quickly, divide instead. A constant ratio means multiplication.
3, 12, 48, 192, ?
Each term is 4 times the last. Answer: 768.
If neither differences nor ratios settle it, the terms themselves are probably from a known family. These four cover most cases:
| Family | Opening terms |
|---|---|
| Squares | 1, 4, 9, 16, 25, 36 |
| Cubes | 1, 8, 27, 64, 125 |
| Primes | 2, 3, 5, 7, 11, 13 |
| Factorials | 1, 2, 6, 24, 120 |
Watch for these families in disguise. A sequence of 4, 9, 25, 49, 121 is not squares of consecutive numbers — it is squares of the primes 2, 3, 5, 7, 11. The next term is 169.
If a sequence alternates up and down, or the differences look random, split it into odd and even positions and check each half separately.
2, 100, 4, 90, 8, 80, ?
Odd positions: 2, 4, 8 — doubling. Even positions: 100, 90, 80 — down 10. Next is an odd position. Answer: 16.
Sometimes each term is built from its own position number. Test whether term n equals something like 3n + 2, or n² − 1. This is the last resort because it is the slowest to check.
Matrix puzzles show a grid of shapes with one cell missing. They feel different from number sequences but reward the same discipline: check a fixed list of properties rather than looking at the picture as a whole.
Scan each of these in turn, first across the rows, then down the columns:
Most matrices use only one or two of these at once. The difficulty comes from combining two simple rules, not from any single rule being hard.
This is the single most useful habit in visual reasoning. Decide what the missing cell should contain before reading the answer choices. Distractors are designed to look plausible, and reading them first pulls your reasoning toward whichever one feels familiar. If you have already committed to a prediction, you are matching rather than being persuaded.
If you cannot find the rule, work backwards. Find one property that is clearly consistent across the grid — often the simplest one, like the number of sides — and eliminate every option that breaks it. Two eliminations turn a one-in-four guess into a coin flip, and that is worth real marks across a test.
Repeating puzzles until you recognise them by sight builds recall, not reasoning. To build the skill that transfers, do three things:
A realistic expectation: practice reliably improves your score on tests of this type, mostly by removing hesitation and misreadings. It is not the same as raising general reasoning ability, and honest guides should not claim otherwise.
Take the differences between consecutive terms first. A constant difference means addition, and a pattern in the differences themselves usually reveals the rule. If that fails, check ratios, then look for squares, cubes, primes or factorials, then check whether two sequences are interleaved.
Scan one property at a time across rows and then down columns: count, rotation, shading, size, position, and whether cells combine. Decide what the missing cell should look like before reading the options, because distractors are designed to look plausible.
Practice reliably improves performance on tests of this type, largely by making rule-checking automatic and reducing misreadings. That is a genuine gain on the test itself, though it is not the same thing as raising general reasoning ability.
Use elimination. Find one property that is clearly consistent across the grid or sequence and rule out every option that breaks it. Removing two options from four doubles your odds, which is worth more across a whole test than spending two minutes on one item.
Take the free IQ Centre test — 18 questions across 5 cognitive domains, with your score and percentile breakdown.
Take the Free IQ Test →