How To: Prime & Composite Numbers & Factors

Here, you will learn all you need to know about prime and composite numbers.

What Is a Prime Number?

A prime number is a number that is great than 1and can only be divided by one and itself.

Examples of prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and much more...

Is 6 a prime number?

No, because 6 can be divided evenly by 2 and 3, and also 1 and 6.

Is 13 a prime number?

Yes, because 13 can only be divided evenly by 1 and 13, which is itself.

What Is a Composite Number?

A composite number is a number that can be divided evenly by 1, itself, and other numbers.

Examples of composite numbers: 4, 6, 8, 9, 12, 14, 15, 16, 18, 20, 21 and much more.

Is 15 a composite number?

Yes, because 15 can be divided evenly by 3 and 5, and also 1 and itself.

Is 29 a composite number?

No, because 29 can only be divided evenly by 1 and 29, which is itself.

Factors

Factors are numbers that when multiplied together, equal a number.

What are factors of 14?

Factors of 14 are 1,2, and 7.

What are factors of 23?

Factors of 23 are 1 and 23.

Practice Time

If you want to practice, answer the questions 1 through 4. Below the questions are the answers.

1. Is 15 a composite number or a prime number? Why?

2. Is 29 a prime number of composite number? Why?

3. What are factors of 27?

4. What are factors of 13?

Answers:

1. 15 is a composite number because it can be divided evenly by 1, 3, and 5.

2. 29 is a prime number because it can only be divided evenly by 1 and 29.

3. Factors of 27 are 1, 3, 9, and 27.

4. Factors of 13 are 1 and 13.

For more fun practice, just play this game! Click the link to play : http://www.sheppardsoftware.com/mathgames/numbers/fruit_shoot_prime.htm

Citations

• http://www.mathsisfun.com/prime-composite-number.html