Editing 3 (section)

=== Divisibility rule ===
A [[natural number]] is [[divisible]] by 3 if the [[digital root|sum of its digits]] in [[base 10]] is also divisible by 3. This known as the [[divisibility rule]] of 3. Because of this, the reverse of any number that is divisible by three (or indeed, any [[permutation]] of its digits) is also divisible by three. This divisibility rule works in any [[positional notation|positional numeral system]] whose [[radix|base]] divided by three leaves a remainder of one (bases 4, 7, 10, etc.).{{Citation needed|date=February 2025}}