Fourth Grade Fractions 9 - Add and Subtract Mixed Numbers Powerpoint Lesson - This is powerful when used as direct instruction in the classroom, on-line, or individually. It teaches students how to add and subtract mixed numbers. Concrete visuals are used to help with understanding. It is designed to continually engage the students as you are teaching. There is a review of skills taught on fractions prior to this lesson. There are 22 effective teaching strategies used in this lesson base