Look at the gaps
Subtract each number from the next. Are the gaps equal, or do they change in a regular way?
A SMALL CHALLENGE. A GOOD DISCOVERY.
Find the
next number.
A few numbers. One hidden pattern. Take a moment, make your choice, and enjoy the “aha”.
- Free to play
- No timer
- Answers explained
24 puzzles · 12 kinds of pattern
Learn to spot the patternsNumber Series
ExpertPuzzle 20 / 24
Choose an answer, then check the pattern.
Read the answer and explanation
Add the previous two
Each term is the previous one plus the one before it.
The next number is 87.
- 3 + 9 = 12
- 9 + 12 = 21
- 12 + 21 = 33
- 21 + 33 = 54
- 33 + 54 = 87
Keep that curiosity going.
Explore reasoning tests, daily challenges and brain games in MindProof for iPhone.
Free core results. Optional Plus features.Read the complete number series solving guide
Number Series
Every pattern has a story.
Start with the gaps. Then look for a repeated operation, a familiar family of numbers, or two patterns taking turns.
Try a different lens
Look for multiplication, squares or cubes. If one rule doesn’t fit, inspect every other number.
Check the whole sequence
A useful pattern explains every shown number, not just the final pair. Then apply it once more.
Twelve ways to find the next number
1 · 3 · 5 · …
Add a little
Try an example 22 · 20 · 18 · …Count backwards
Try an example 1 · 2 · 4 · …Multiply each time
Try an example 162 · 54 · 18 · …Divide each time
Try an example 3 · 8 · 14 · …Watch the gaps grow
Try an example 1 · 4 · 9 · …Spot the squares
Try an example 1 · 8 · 27 · …Look for cubes
Try an example 1 · 2 · 3 · …Add the previous two
Try an example 5 · 15 · 18 · …Alternate the steps
Try an example 1 · 60 · 5 · …Untangle two patterns
Try an example 2 · 6 · 14 · …Multiply, then add
Try an example 2 · 3 · 5 · …Recognize the primes
Try an exampleA few things worth knowing
Is this an IQ test?
No. These are number-pattern puzzles for practice and enjoyment. They don’t calculate an IQ score or measure your intelligence.
Is there only one possible answer?
A finite sequence can have many mathematical continuations. Each puzzle here uses a conventional pattern that explains all shown numbers. The explanation tells you which rule was intended.
Will my friend see the same puzzle?
Yes. The share link points to a fixed question and answer set. Your choices and results are not included.
Can I play without an account?
Yes. Choose a puzzle and play. This page does not save your answers or require a download.
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