Composite number definition is an integer (number) that is exactly divisible by one positive number (integer) other than itself or 1. The composite number is a positive integer that can be factorized into two or more other positive numbers (integers). We can also define composite number as a number that is a multiple of at least 2 integers other than itself and 1. The prime numbers are not composite numbers or in other words integers that have no integral factors but itself and 1 are not composite number. The examples below will help to better understand composite numbers.
Example 1: Identify which of the following numbers are composite numbers and why.
a. 24
b. 82
Solution: To identify composite numbers we need to see it can be factorized into 2 or more positive numbers other than itself and 1.
a. 24 can be divided by 2, 3, 4, 6, 8 and 12 therefore it is a composite numbers
b. 82 can be divided by 2, 41 therefore it is a composite number
Example 2: Which of the following statements are true and false and why?
a. 43 is a composite number
b. 22 is a composite number
c. 53 is not a composite number
Solution:
a. False that 43 is a composite number since 43 can be divided by 1 and 43 and no other integer.
b. True since 22 can be divided by 2, 11.
c. True since 53 can be divided by 1 and 53.