The LCM is a useful tool to use when comparing fractions and finding common denominators.

[Free Registration/Login may be required to access all resource tools.] This video gives steps of finding common denominators and then adding and subtracting multiple fractions together. After the video, there are practice problems...

[Free Registration/Login may be required to access all resource tools.] In this lesson students find sums of fractions with different denominators by renaming them with common denominators. Students examine guided notes, review guided...

This is an excellent resource to visually illustrate adding and subtracting fractions by finding the lowest common denominator.

Add and subtract rational expressions like a pro after you use this site. Finding common denominators is made easy with this tutorial. Try the example problems to test your knowledge, then check the solutions. The 'Topic Index' page...

This site explains how to find the least common denominator. Also provides games to work on this skill.

In this Math Maven mystery, read the legend of Pirate Ringold and his treasure and help Frieda Finditall figure out how much gold there is left to find on this old ship. Your knowledge about addition and subtraction with fractions will...

This personal site explains how to add fractions with different denominators by finding the least common denominator. Gives problems and games to practice this skill.

In this activity, students will compare ratios with different denominators, and then with common denominators. They will also find unit rates.

Students simplify fractions by dividing the numerator and denominator by the GCF (the greatest common factor). They check their work by using a calculator.

This site is a question and response to a student asking Dr. Math about the greatest common divisor, he gives an interesting way to find the gcd, as well as the button on calculators which commonly does the math for you.

[Free Registration/Login may be required to access all resource tools.] Find differences of fractions with different denominators by renaming them with a common denominator.

In this interactive website students practice various skills including adding fractions with common denominators, adding fractions with different denominators, adding decimals, finding equivalent fractions, and calculating averages.

Gives a very basic overview of fractions and their parts. Discusses adding, multiplying, and finding a common denominator.

Use the examples to find the least common denominator in order to add and subtract rational expressions.

[Free Registration/Login may be required to access all resource tools.] In this lesson students find the difference of mixed numbers by using borrowing and renaming. Students examine guided notes, review guided practice, watch...

Finding common denominators is no problem with Purplemath. Use this lesson to learn how to add and subtract rational expressions with these great examples.

Explains how to find a common denominator between two rational expressions and how to reduce a fraction that involves factoring. There are example problems solved, problems for the student to attempt, and answers to the student problems....

[Free Registration/Login may be required to access all resource tools.] Determine the factors of given numbers using divisibility rules.

[Free Registration/Login may be required to access all resource tools.] In this lesson students find the sum of mixed numbers by renaming fractions with a common denominator. Students examine guided notes, review guided practice, watch...

Practice finding the lowest term name for a variety of different fractions using a number line.

The process of factoring and canceling is used to simplify, multiply, and divide rational expressions. Adding and subtracting rational expressions is also demonstrated, including finding common denominators.

Use this Web site to practice finding equivalent fractions using a matching game format. CCSS.Math.Content.3.NF.A.3.a Understand two fractions as equivalent (equal) if they are the same size, or the same point on a number line.

The mathematics tutorial investigates how to simplify rational equations, find the least common denominator as well as how to solve rational equations. There are notes, examples and an interactive applet as well as a vocabulary puzzle.