So, you have a large number that is being divided by a smaller number. Learn a few tricks to make dividing a little more palatable. 2-is it even, 3-do the digits add up to a multiple of three, 5-does it end in 0 or 5, 6-is it divisible...

What do divisibility and factoring have to do with each other? Well, if a whole number is the divisor and a whole number is the answer then both those numbers are factors of the number being divided. But if the answer is a decimal number...

How do you find the factors of a given number? The teacher will show you how to use a table, test out your answers, and then write all your factors in a list. If you know the divisibility rules, that will also help you out.

This video explains how to test whether a number is divisible by a list of other numbers under 10. Practice problems are available. [6:26]

This video shows how to determine the prime factorization of a number to determine divisibility. Practice problems are available. [8:13]

This video illustrates the divisibility rules for factors 2, 3, 4, 5, 6, 8, 9 and 10.

This video shows how to determine the prime factorization of a number to determine divisibility.

A video showing how to find the factors of given numbers.

Worked example of basic divisibility tests.

Why you can add the digits to see if something is divisible by 3.

Why you can test divisibility by 9 by just adding the digits.

Watch this video tutorial to learn divisibility rules for 3 and 9. [7:26]

Video tutorial uses examples to reinforce understanding of divisibility rules for 2,4,5, and 25. [6:06]

This QuickTime movie provides an opportunity to learn and practice the divisibility rules. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.

This video focuses on finding the square of a whole number and the square root of a perfect square. In order to do this, you will first learn how to do prime factorization, a method to find the prime factors of a number. [1:58]

This video teaches you how to estimate square roots which are not perfect squares without using a calculator. Explanations and examples are included. [3:45]

This lesson grouping provides students with a wide variety of tricks and techniques to determine if one number is divisible by another number. It is 1 of 6 in the series titled "Divisibility."

This lesson introduces the rules of divisibility. It is 10 of 11 in the series titled "Divisibility Rules."

This lesson introduces the rules of divisibility. It is 2 of 11 in the series titled "Divisibility Rules."

This lesson introduces the rules of divisibility. It is 7 of 11 in the series titled "Divisibility Rules."

This lesson will go through the steps involved in using a ruler to measure length in centimeters and millimeters. It is 3 of 4 in the series titled "Millimeters & Centimeters."

This lesson will go through the steps involved in using a ruler to measure length in centimeters and millimeters. It is 4 of 4 in the series titled "Millimeters & Centimeters."

This lesson will go through the steps involved in using a ruler to measure length in centimeters and millimeters. It is 1 of 4 in the series titled "Millimeters & Centimeters."

This lesson will go through the steps involved in multiplying a two digit number by a 1 digit number. It is 3 of 4 in the series titled "Multiplying 2 Digit Numbers by 1 Digit Numbers."