How to Add Three Fractions with Unlike Denominators

Math with Mr. J

This instructional math video guides students through the process of adding three fractions with unlike denominators. Using a clear, handwritten chalkboard aesthetic, the narrator breaks down the procedure into four manageable steps: finding a common denominator, renaming the fractions, performing the addition, and simplifying the final result. The video provides two complete, worked-out examples that demonstrate how to handle different sets of denominators and how to convert the resulting improper fractions into mixed numbers. Key mathematical themes include finding the Least Common Multiple (LCM) to establish a common denominator, creating equivalent fractions, and understanding the relationship between improper fractions and mixed numbers. The video reinforces the concept that the methods used for adding two fractions apply seamlessly to adding three or more, helping students build confidence in extending their existing skills to more complex problems. For educators, this video serves as an excellent direct instruction tool or review resource for 5th and 6th-grade math units on operations with fractions. The pacing is deliberate and easy to follow, making it suitable for students who struggle with the multi-step nature of fraction arithmetic. The visual representation of listing multiples helps demystify how common denominators are found, while the step-by-step renaming process provides a strong model for student work.