Divisibility Tests

A divisibility test tells you whether one number divides exactly into another without doing the whole division. In NSW Year 7 maths (NESA outcome MA4‑IND‑C‑01) these tests are a quick way into factors and primes.

You will look at the last digit or last few digits to test for 2, 4, 5, 8 and 10, use the digit sum to test for 3 and 9, combine tests for 6, 12 and 45, find a missing digit that makes a number divisible, and find the smallest number past a target that passes a test. Packing bottles into six-packs is one real use. It is part of Year 7 Whole Numbers.