Prime Factors Worksheets
What Are Prime Factors? The numbers we multiply to get another number are known as the factors. For example, when we multiply 3 and 5, we get 15 (3 x 5 =15). That means that 3 and 5 are the factors of 15. Most numbers have more than one set of factors. Different pairs of numbers, when multiplied, give us the same answer. For instance, 12 can have factors of 3 x 4, 6 x 2, and 1 x 12. However, we have numbers that can only be factored by 1 or by itself. These factors are known as prime factors. These include 2,3, 5,7,11, and 13. Number 1 is usually not regarded as the prime factor as it goes into everything. Often you are required to find out the prime factorization of a number won’t include 1 but have every copy of the prime factor. If we have to do prime factorization of 8, it would be 2x2x2 and not only 2. Although 2 is the only factor, we need three 2s to make an 8. So, the prime factorization of number 8 would include all three copies of 2.
Demonstrates how to find the prime factors of a number. Also includes practice problems.View worksheet
Uses a larger more difficult numbers than the basic lesson.View worksheet
Independent Practice 1
Find all the prime factors of each number. The answers can be found below.View worksheet
Independent Practice 2
20 practice problems that review prime factors. The answers can be found below.View worksheet
12 problems to reinforce the lessons and practice pages. An example is provided.View worksheet
10 problems that test prime factoring skills.View worksheet
Homework and Quiz Answer Key
Answers for the homework and quiz.View worksheet
Lesson and Practice Answer Key
Answers for both lessons and both practice sheets.View worksheet
A factor is a whole number that divides exactly into a larger number without leaving a remainder. To factor a number, identify all of its prime factors by breaking the number down into its factors until all of the factors are prime.