Divisibility rules for 3, 6, and 9

Learning Objectives State the divisibility rule for 3. State the divisibility rule for 9. State the two-part divisibility rule for 6. Determine if a multi-digit number is divisible by 3 by summing its digits. Determine if a multi-digit number is divisible by 9 by summing its digits. Determine if a multi-digit number is divisible by 6 by checking for divisibility by both 2 and 3. Apply the rules to quickly check answers for division problems involving 3, 6, or 9. Can you tell if 1,458 cookies can be shared equally among 9 friends without doing any division? 🍪 Let's learn a math superpower to find out! In this tutorial, you will learn simple shortcuts called divisibility rules. These rules are tricks to see if a number can be divided perfectly by 3, 6, or 9 without le...

TermDefinitionExample DivisibleA number is 'divisible' by another number if it can be divided exactly, with a remainder of 0.15 is divisible by 3 because 15 ÷ 3 = 5 with a remainder of 0. DigitAny of the numerals from 0 to 9 that are used to form a number.In the number 742, the digits are 7, 4, and 2. Sum of the DigitsThe result you get when you add all the digits of a number together.For the number 742, the sum of the digits is 7 + 4 + 2 = 13. Even NumberA whole number that can be divided exactly by 2. Even numbers always end in 0, 2, 4, 6, or 8.56 is an even number because it ends in 6. Odd NumberA whole number that cannot be divided exactly by 2. Odd numbers always end in 1, 3, 5, 7, or 9.83 is an odd number because it ends in 3. FactorA number that divides into another numbe...

Divisibility Rule for 3 A number is divisible by 3 if `Sum(its digits)` is divisible by 3. First, add up all the digits in the number. Then, check if that sum can be divided by 3. If the sum is divisible by 3, the original number is too. Divisibility Rule for 9 A number is divisible by 9 if `Sum(its digits)` is divisible by 9. This is very similar to the rule for 3. Add up all the digits. If that sum can be divided by 9, the original number is also divisible by 9. Divisibility Rule for 6 A number is divisible by 6 if `(it is divisible by 2)` AND `(it is divisible by 3)`. This is a two-part rule. First, check if the number is even (ends in 0, 2, 4, 6, or 8). Second, use the divisibility rule for 3. If the number passes BOTH tests, it is divisible by 6.