Tests for divisibility

Puzzles

• elevenWhat is the test to see if a number is divisible by eleven?
• nineWhat is the test to see if a number is divisible by nine?
• sevenWhat is the test to see if a number is divisible by seven? Added material
• small.divisorsWhat are the tests to see if a number is divisible by 2, 3, 4, ... New
• threeWhat is the test to see if a number is divisible by three?