How to Subtract Fractions with Unlike Denominators

Math with Mr. J

This instructional video provides a clear, step-by-step guide on how to subtract fractions with unlike denominators. The presenter, Mr. J, uses a digital blackboard format to walk viewers through two distinct examples, demonstrating a systematic four-step process: finding a common denominator, renaming the fractions, subtracting the numerators, and simplifying the final answer. The video emphasizes the importance of finding the Least Common Multiple (LCM) to create equivalent fractions before performing the subtraction. The content focuses on key arithmetic concepts including Least Common Multiple (LCM), equivalent fractions, and simplifying fractions to their lowest terms. It specifically addresses the procedural rules of fraction subtraction—highlighting that denominators must match before subtraction can occur and that operations applied to the denominator must also be applied to the numerator to maintain equivalence. The second example intentionally includes a final answer that requires simplifying, reinforcing the need to check work for simplest form. For educators, this video serves as an excellent direct instruction tool or review resource for upper elementary and middle school math classes. Its methodical pacing and visual breakdown of finding multiples make it particularly useful for students who struggle with the multi-step nature of fraction operations. The clear handwritten style allows students to see exactly how they should organize their own work on paper, making it a practical model for note-taking and independent practice.