Adding & Subtracting Fractions PowerPoint Slides. Mini Lesson. Including Adding Fractions Using the Least/Lowest Common Multiple. 20 PowerPoint Slides.These PowerPoint slides focus on adding and subtracting fractions. It can be used as a mini-review or lesson with any students to help reinforce the concept of adding and subtracting fractions. It is divided into three sets of slides. The first set of slides focuses on introducing students how to add and subtract fractions. The other two sets of s