Here is a quick number-sequence challenge:
18, 10, 6, 4, ?
Before reading the explanation, try to identify what changes between each pair of numbers.
Look at the Differences
- 18 → 10 means subtract 8.
- 10 → 6 means subtract 4.
- 6 → 4 means subtract 2.
The amount being subtracted is cut in half each time:
8 → 4 → 2 → 1
If we continue that pattern, the next calculation is:
4 − 1 = 3
So the Intended Answer Is 3
Using the simplest halving-difference pattern, the sequence becomes:
18, 10, 6, 4, 3
Could a Number Sequence Have Another Answer?
Yes. A short sequence can sometimes be continued using more than one mathematical rule. Brain teasers usually expect the simplest consistent pattern, which is why 3 is the natural answer here.
A Useful Trick for Number Puzzles
When a sequence is not obvious, first compare consecutive numbers. Check whether the differences are increasing, decreasing, doubling, halving, or repeating. Looking at the differences often reveals the intended pattern quickly.