Divisibility Rules for 3, 6 and 9 to Find the Common Factors of Numbers I Lesson From the previous lesson, you have learned the divisibility rules for 2, 5, and 10 in finding the factors of large numbers. This time you will learn the rules to determine if the numbers is divisible by 3, 6, 9. After go- ing through this lesson, you are expected to use divisibility rules for 3, 6 and 9, to find the common factors of numbers. Learning Task 1. Observe the following divisibility rules in the example below. 1.) Is 27 divisible by 3? Yes, because the sum of its digit is divisible by 3 2+7= 9 9 is divisible by 3 2.) Is 144 divisible by 6? Yes, because 144 is divisible by 2 and 3. So, it is also divisible by 6 3.) 87651 divisible by 9? Yes, because of its digit is divisible by 9. (8 + 7 + 6 + 5 + 1 = 27 is divisible by 9​