Prime and composite numbers are an important algebra concept when starting fourth grade math. Prime numbers are whole numbers that can only be divided by 1 and itself, while composite numbers are whole numbers that can be divided by numbers other than 1 and itself. To learn more about these numbers and how they are used in math, see the bottom of the page.
A Guide to Prime and Composite Numbers
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Prime numbers are whole numbers that can only be divided by 1 and itself. Prime numbers do not, however, include the number 1, so the smallest prime number is 2. Some examples of prime numbers are 3, 5, 7, 11, and 13.
Composite numbers are also whole numbers, but they are different from prime numbers because they can be divided by numbers other than 1 and itself. The number 1 is also not considered a composite number, so 4 is the smallest composite number. Even numbers (excluding 2) are all examples of composite numbers.
Factors are another mathematical concept used to define prime numbers. Factors are the numbers that are multiplied together to get a final product. For example, in the equation 3 × 2 = 6, 3 and 2 are both factors. Using this definition of factors, we can now say that a prime number is any number that has only two factors that are 1 and the number.
Prime and composite numbers are some of the basic building blocks of math and can be used to help understand multiplication and division concepts. To get more practice using prime and composite numbers, check out our worksheets, games, and exercises!