Divisibility Patterns

Number Theory · Axiom Academy

Discover the hidden patterns that reveal when numbers divide evenly. Enter any number below and watch what happens to its digits. Can you spot a pattern? Click on a divisor to highlight all numbers from 1-100 that are divisible by it. What patterns do you see? The rule for divisibility by 11 is particularly elegant. Enter a number and watch the alternating sum. What happens when you need to check for divisibility by composite numbers like 6, 12, or 15?

This is the written version of the interactive lesson above. See the full Number Theory course.