11+ Number Sequences: 5 Patterns That Solve Almost Every Question
By Simply Eleven Plus · Updated 25 October 2026 · 5 min read
Number sequences appear in Maths and Verbal Reasoning papers. Almost all of them use one of five patterns. Teach your child to check these in order, and most questions take seconds.
1. Adding or taking away the same amount
Example
3, 7, 11, 15, ?
Each number is 4 more than the one before. 15 + 4 = 19.
Answer: 19
2. The gaps change in a pattern (second differences)
Example
2, 5, 10, 17, 26, ?
The gaps are 3, 5, 7, 9, going up by 2 each time. The next gap is 11, and 26 + 11 = 37.
Answer: 37 (These are also the square numbers plus one.)
3. Multiplying or dividing
Example
3, 6, 12, 24, ?
Each number is double the one before. 24 × 2 = 48.
Answer: 48
4. Two sequences taking turns
Example
4, 20, 7, 18, 10, 16, ?
The gaps look random, so split it. Odd positions: 4, 7, 10 (+3). Even positions: 20, 18, 16 (−2).
The missing number is in the odd positions: 10 + 3 = 13.
Answer: 13
5. Adding the two numbers before
Example
1, 1, 2, 3, 5, 8, ?
Each number is the sum of the two before it: 5 + 8 = 13.
Answer: 13
Also learn to recognise
| Name | Start of the sequence |
|---|---|
| Square numbers | 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 |
| Cube numbers | 1, 8, 27, 64, 125 |
| Triangular numbers | 1, 3, 6, 10, 15, 21, 28 |
| Prime numbers | 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 |
Always check your answer fits every step of the sequence, not just the last one. Letter series work the same way: see 11+ letter sequences.
Practise it
The method only sticks with practice. Try number sequence questions on Simply Eleven Plus, free to start, with instant marking and an explanation for every answer, or sit a free live mock exam to practise under real exam conditions.
Free 11+ live mock exams
Let your child sit a real-time, timed mock paper online, then go through the trickiest questions together. It’s free.