Home
#### Algebra and Pre-Algebra Lessons

Algebra 1 | Pre-Algebra | Practice Tests | Algebra Readiness Test
#### Algebra E-Course and Homework Information

Algebra E-course Info | Log In to Algebra E-course | Homework Calculator
#### Formulas and Cheat Sheets

Formulas | Algebra Cheat Sheets

Home » Fractions » Factor Trees

# Factor Trees - Using Prime Factorization to Identify the GCF

## Example 1

## Part 1 - Prime Factorization for 175

## Prime Factorization for 250

## Greatest Common Factor for 175 & 250

## Example 2

# Like This Page?

## Other Fraction Pages You Might Like

You've probably heard or learned about prime factorization (factor trees) in your basic math classes. You probably don't use this on a daily basis, therefore, you may not remember how to find the prime factorization or you may not remember why it is used.

Let's start by defining a prime number.

A prime number is a positive integer, greater than 1, whose only factors are 1 and itself.

Prime numbers can be used to find the greatest common factor for a set of numbers.

I know you are still wondering WHY and HOW! Let's say you need to find the greatest common factor for the numbers 175 and 250. Since these numbers are a little larger, identifying the common factors is not quite as easy. This is where prime factorization may be a little faster. Many people also call prime factorization the process of making a **factor tree**.

First I'm going to make a factor tree for 175. Take a look....

Now that we know the prime factorization for 175 and 250, we can identify the greatest common factor.

Yes, it looks like a long complicated process, but it's not too bad. Yes, it does require a little more writing, but if you are working with larger numbers, prime factorization is the fastest way to identify the greatest common factor.

This first example is thoroughly explained and labeled, in order to make sure that you understand the process. Let's look at one more example, without as many labels, so that you can see how this process should look on your paper.

Factor trees (or prime factorization) can be an easy way to find the greatest common factor for two large numbers. Simply find all of the prime factors and identify the common factors. Multiply your common factors together and you end up with the greatest common factor for both numbers!

Now that you know two ways to find the greatest common factor of two numbers, you are ready for the next lesson on equivalent fractions.

- Prime and Composite Numbers
- Simplifying Fractions
- Comparing Fractions
- Mixed Numbers and Improper Fractions
- Adding Fractions with Like Denominators
- Adding Fractions with Unlike Denominators
- Subtracting Fractions with Like Denominators
- Subtracting Fractions with Unlike Denominators
- How to Multiply Fractions
- Multiplying Fractions by Whole Numbers
- Multiplying Mixed Numbers

Sign Up for Algebra Class E-courses

Click here to retrieve a lost password.

Custom Search

- FREE Solving Equations E-course
- Algebra Class E-course
- Algebra Class Products
- Algebra Practice Test
- Algebra Readiness Test
- Homework Answer Calculator
- Practice Worksheets

- Site Map
- Pre-algebra Refresher
- Solving Equations
- Graphing Equations
- Writing Equations
- Systems of Equations
- Inequalities
- Functions
- Exponents & Monomials
- Polynomials
- Quadratic Equations
- Algebra 1 Final Exam

- SAT Online Course
- Algebra Cheat Sheets - Very Popular!!
- Algebra Formulas
- Online Resources
- Contact Me
- I Want to Hear From You!
- Algebra Blog
- About Me

Copyright © 2009-2015 Karin Hutchinson ALL RIGHTS RESERVED

## Comments

We would love to hear what you have to say about this page!