Divisibility Rules, Learned as Four Families

04 Try it yourself Interactive

Apply any family rule, one step at a time

Choose a number and a divisor. The console picks the family, explains why that family’s mechanism applies to this divisor, then works the rule. Try the same number against 4, 9 and 11 to see three different mechanisms decide the same question.

3564 tested for 11

alternating sum = 0

The co-prime options 6 and 15 run two sub-rules and need both to pass. 8 deliberately has no split option, for the reason given in section 03.

Press Next to work through it one step at a time.

Divisor–

Rule used–

Key figure–

Divisible?–

step 0 / 0