# Divisibility and factors

A number is considered divisible by another number (divisibility) when the result of the division is an integer and there is no remainder. The number which divides that number is called a factor of that number or its divisor. Division is an operation that is the opposite of multiplying and the property that a number can be divided by another number is called divisibility.
For example: If you divide the number 16 with the number 2, you will get the number 8 as a result and no remainder. That means that the number 16 is divisible by the number 2 and that 2 is a factor of 16. But if you divide the number 16 with the number 3, you will get the number 5 as a result with 1 as the remainder. This means that 16 is not divisible by 3 and 3 is not a factor of 16.

The basic rules that can help you determine whether a number can be divided by another number (and which one) are ilustrated in the picture below. These rules are particularly useful in prime factorization or finding the least common multiple or the greatest common factor. ## Divisibility exams for teachers

 Exam Name File Size Downloads Upload date Positive integers Divisibility of positive integers – very easy 0 B 4441 January 1, 1970 Divisibility of positive integers – easy 0 B 3172 January 1, 1970 Divisibility of positive integers – medium 0 B 3798 January 1, 1970 Divisibility of positive integers – hard 0 B 2954 January 1, 1970 Positive decimals Divisibility of positive decimals – very easy 0 B 1489 January 1, 1970 Divisibility of positive decimals – easy 0 B 1432 January 1, 1970 Divisibility of positive decimals – medium 0 B 1364 January 1, 1970 Divisibility of positive decimals – hard 0 B 1393 January 1, 1970 Positive fractions Divisibility of positive fractions – very easy 0 B 1442 January 1, 1970 Divisibility of positive fractions – easy 0 B 1289 January 1, 1970 Divisibility of positive fractions – medium 0 B 1419 January 1, 1970 Divisibility of positive fractions – hard 0 B 1196 January 1, 1970 Positive mixed numbers Divisibility of positive mixed numbers – easy 0 B 1325 January 1, 1970 Divisibility of positive mixed numbers – medium 0 B 1186 January 1, 1970 Divisibility of positive mixed numbers – hard 0 B 1130 January 1, 1970 Positive improper fractions Divisibility of positive improper fractions – very easy 0 B 1194 January 1, 1970 Divisibility of positive improper fractions – easy 0 B 1098 January 1, 1970 Divisibility of positive improper fractions – medium 0 B 1061 January 1, 1970 Divisibility of positive improper fractions – hard 0 B 1173 January 1, 1970 Divisibility of positive improper fractions – very hard 0 B 1065 January 1, 1970 Non positive integers Divisibility of integers – very easy 0 B 1359 January 1, 1970 Divisibility of integers – easy 0 B 1364 January 1, 1970 Divisibility of integers – medium 0 B 1610 January 1, 1970 Divisibility of integers – hard 0 B 1714 January 1, 1970 Non positive decimals Divisibility of decimals – very easy 0 B 1204 January 1, 1970 Divisibility of decimals – easy 0 B 1334 January 1, 1970 Divisibility of decimals – medium 0 B 1148 January 1, 1970 Divisibility of decimals – hard 0 B 1441 January 1, 1970 Non positive fractions Divisibility of fractions – very easy 0 B 1175 January 1, 1970 Divisibility of fractions – easy 0 B 1250 January 1, 1970 Divisibility of fractions – medium 0 B 1145 January 1, 1970 Divisibility of fractions – hard 0 B 1228 January 1, 1970 Non positive mixed numbers Divisibility of mixed numbers – easy 0 B 1216 January 1, 1970 Divisibility of mixed numbers – medium 0 B 1182 January 1, 1970 Divisibility of mixed numbers – hard 0 B 1101 January 1, 1970 Non positive improper fractions Divisibility of improper fractions – easy 0 B 1407 January 1, 1970 Divisibility of improper fractions – medium 0 B 1311 January 1, 1970 Divisibility of improper fractions – hard 0 B 1467 January 1, 1970

There are tricks and shortcuts in the process of determination whether a number is divisible by another number.
Every number, including prime numbers, is divisible by the number 1 and itself.
All even numbers (those ending in 0, 2, 4, 6 or 8 ) are divisible by 2.
If you calculate the sum of all the digits in a number and that sum is divisible by 3, then the number is divisible by 3 as well.
A number is divisible by 4 if the last two digits in that number are divisible by 4.
Every number ending in 0 or 5 is divisible by the number 5.
A number is divisible by 6 if it is also divisible by 2 and 3.
If the last three digits in a number are divisible by 8, then that whole number is divisible by 8.
The same rule applies for checking if a number is divisible by the number 9 as it does for number 3. If the sum of all digits in the number is divisible by 9, then the entire number is divisible by 9.
Every number ending in 0 is divisible by the number 10.

## Factoring exams for teachers

 Exam Name File Size Downloads Upload date Factoring all positive factors 0 B 2636 January 1, 1970 Factoring numbers without exponents 0 B 1623 January 1, 1970 Factoring with exponents 0 B 2278 January 1, 1970

## Divisibility and factoring worksheets for students

 Worksheet Name File Size Downloads Upload date Positive Divisibility of positive integers 0 B 2057 January 1, 1970 Divisibility of positive decimals 0 B 1336 January 1, 1970 Divisibility of positive fractions 0 B 1159 January 1, 1970 Divisibility of positive mixed numbers 0 B 1085 January 1, 1970 Divisibility of positive improper fractions 0 B 1147 January 1, 1970 Non positive Divisibility of integers 0 B 1390 January 1, 1970 Divisibility of decimals 0 B 1208 January 1, 1970 Divisibility of fractions 0 B 1245 January 1, 1970 Divisibility of mixed numbers 0 B 1111 January 1, 1970 Divisibility of improper fractions 0 B 1177 January 1, 1970 Factoring numbers Factoring 0 B 2394 January 1, 1970