John Zimmerman, http://www.algebratesthelper.com explains how to add or subtract fractions using the least common denominator, which is the least common multiple for the denominators of the fractions. Once the fractions are given a common denominator by multiplying the numerator and denominator of each fraction by the appropriate number, then the fractions can be added or subtracted by adding or subtracting the numerators, and leaving the denominator the same.

In algebra, adding and subtracting fractions is easy when you find the common denominator. This video shows you how to convert fractions for the common denominator. After you determine the common denominator, you can add and subtract fractions, including story problems, with ease.

strategy to multiply and divide fractions.wmv 從學分數練習聽力

說明：

This video will give teachers a model to help them teach their own students how to multiply and divide fractions. This video shows an easy way to remember the steps to multiply and divide fractions. It uses connections to prior learning for middle school low performing students and English language learners (ELL students). The video can also be used by 4th grade and 5th grade teachers for grade level instruction of fractions. These strategies are easy for students to remember and for teachers to teach, they are easy and understandable using academic language giving easy reminders for academic vocabulary. Engaging visuals to help students remember how to multiply and divide fractions. This video should be used by teachers and parents as a model of how to teach fractions. It follows a simple procedure that makes multiplying and dividing fractions easy. It has tricks on how to remember strategies and academic vocabulary. Teachers will love this coaching video because they will be able to reach their students in 4th grade, 5th grade, 6th grade, 7th grade, or 8th grade. These visuals and easy steps will help low performing middle school students understand, especially students of color and ELL students, helping to close the achievement gap. This understanding of fractions as a division problem will give students the foundation for algebra. These coaching videos for teachers will give them uncluttered, understandable strategies for their students. These easy steps will be remembered by the students and they will gain confidence in their math skills giving them the background for future STEM classes. This video will teach teachers how to teach fractions and an easy way to remember the division of fractions and how to apply the reciprocal. It will also help teachers prepare students for the STAR test. Preparation for standardized testing such as CST in California. This video can be used by administrators for staff development for struggling teachers. Remediation programs and after school programs can use this video for guidance in teaching fractions.