As a math interventionist, one topic that I see students struggling with year after year is adding and subtracting fractions with unlike denominators. Earlier in my career, I remember struggling through a fraction unit, trying the 4 square method, multiplication charts, and anything I could remember from my own days in school or find on Pinterest, all without seeing much growth. I knew I needed to do something differently, leading to the creation of my new favorite fraction strategy! Since then, I’ve used this strategy with students year after year and will never go back!
The Fraction List strategy is based on equivalent fractions and the idea that when we change fractions to have a common denominator, we are really trading in the original fraction for another equal fraction that will work better in this problem.
My middle school students have had a lot of success with this strategy and often prefer it over other faster methods due to how easy it is to understand!
To use the Fraction List Strategy, start by writing out each of the two fractions from the problem with a space to the right of them. Use that space to record a list of equivalent fractions to the original fraction by multiplying the top and the bottom of the fraction by the same number. I like to start with times 2, then 3, then 4, then 5. Repeat with the second fraction. Looking at your lists, identify a fraction from each list that have the same denominator, remembering that the original fractions are still a part of the list! I have my students circle these fractions. Then, we rewrite the original problem using our new fractions and TA-DA! You now have a problem that means the same thing, but is so much easier to solve.
If your students are struggling with this strategy after some practice, I recommend assessing their understanding of equivalent fractions. A strong foundation in fraction equivalency is essential to many math skills, including adding and subtracting fractions with unlike denominators!
Are you ready to give your fraction unit a refresh? I can’t wait to hear how this strategy works for you in the comments!
