Next Number in Sequence Calculator
Enter any number sequence or puzzle with missing terms (e.g. 2, 5, 10, 17, 26, ? or 4, 9, ?, 25, 36). The solver determines the underlying rule, difference tables, and next terms.
Separate numbers with commas or spaces. You can put ? at the end or anywhere in the middle.
Enter your sequence to find the pattern
Hit Find Next Number or pick a preset above to calculate the formula and step-by-step working.
Difference Table / Progression
Step-by-Step Rule Derivation
Next Projected Terms
How to Solve Missing Number Sequences in Aptitude Tests
Numerical reasoning and IQ tests use 5 standard patterns. Follow this fast checklist when taking timed tests:
1. Arithmetic (Linear)
Constant addition or subtraction: e.g. 3, 7, 11, 15 (+4).
2. Quadratic / Polynomial
First differences grow by a constant: e.g. 2, 5, 10, 17 (+3, +5, +7 β 2nd diff = +2).
3. Geometric (Multiplier)
Constant multiplication: e.g. 3, 6, 12, 24, 48 (Γ2).
4. Alternating / Two-Stream
Two separate patterns mixed together: 2, 40, 4, 35, 6, 30 (odds: +2, evens: -5).
5. Fibonacci / Sum of Previous
Each term is the sum of preceding numbers: 1, 1, 2, 3, 5, 8, 13.
6. Two-Step Operations
Multiply and add/subtract: 3, 7, 15, 31 (Γ2 + 1).