A number maze with a rule. In the factors and multiples version, each step goes to a number that divides the one you are on, or that it divides: from 12 you could step to 4, 6, 24 or 36, but not to 10. In the primes version you may only step on prime numbers; in the times-table version, only on multiples of the chosen number.
Only one trail works. Every number that isn’t on the trail breaks the rule with all of its neighbours — so each step is a little factor or prime check.
Perfect practice for factors, multiples, primes and times tables, with a puzzle to solve along the way.
Find the only trail from start to flag, stepping across or down to numbers that follow the rule.
The full guide, with a worked example and common mistakes: How to play Factor Trail.
No — a prime has exactly two factors, 1 and itself. 1 has only one.
The trail never runs alongside itself, so there is never a shortcut.
Yes — every number off the trail breaks the rule with all its neighbours.