Lesson objective: Solve word problems involving mixed number addition and subtraction by using a problem-solving strategy to check for understanding and accuracy.

This lesson helps to build procedural skill with adding and subtracting mixed numbers. Bar models are used here because they support the relationship between addition and subtraction. This work develops students' understanding that we can use visual models and equations to represent situations involving addition and subtraction of fractions with the same whole and like denominators.

Students engage in Mathematical Practice 2 (Reason abstractly and quantitatively) as they work with problem situations.

**Key vocabulary:**

- fraction
- mixed number
- problem solving strategy