The purpose of this lesson is to help students remember from earlier grades how tape diagrams can be used to represent operations. There are two roles that tape diagrams (or any diagrams) can play: helping to visualize a relationship, and helping to solve a problem. The focus here is the first of these, so that later students can use diagrams for the second of these. In this lesson, students both interpret tape diagrams and create their own.
Note that the terms “solution” and “variable” aren’t defined until the next lesson, nor should any solution methods be generalized yet. Students should engage with the activities and reason about unknown quantities in ways that make sense to them.
- Draw tape diagrams to represent equations of the forms $x+p=q$ and $px=q$.
- Interpret (orally and in writing) tape diagrams that represent equations of the form $p+x=q$ or $px=q$.
- Use tape diagrams to find unknown values in equations of the forms $x+p=q$ and $px=q$ and explain (orally) the solution method.
Let's see how tape diagrams and equations can show relationships between amounts.
- I can tell whether or not an equation could represent a tape diagram.
- I can use a tape diagram to represent a situation.