Divisibility rules provide ways to determine if a number is divisible by another number without performing long division. The document outlines divisibility rules for numbers 1-10. It explains that for divisibility by 2, 4, 5, and 10 you check the last digit(s) of the number. For divisibility by 3 and 9 you sum the digits. For divisibility by 6 you check divisibility by both 2 and 3. Divisibility by 7 involves subtracting twice the last digit from the remaining digits. Divisibility by 8 checks the last three digits.