# 3.8: Problem-Solving Strategies: Use a Formula

**At Grade**Created by: CK-12

## Learning Objectives

At the end of this lesson, students will be able to:

- Read and understand given problem situations.
- Develop and apply the strategy: Use a Formula.
- Plan and compare alternative approaches to solving problems.

## Vocabulary

Terms introduced in this lesson:

- procedure

## Teaching Strategies and Tips

In this lesson, students solve applied problems using the four-step problem solving plan.

In Example 2, providing a drawing of each stage of the climb may help students organize the given information.

In Example 4, students can check their answers by working backwards. Consider the fraction remaining after each deduction.

In the *Review Questions,* use the answer to Problem 6 to solve Problem 7.

## Error Troubleshooting

General Tip: Remind students to *interpret* their answer in Step 4 of the problem solving plan. This gives students a moment to determine whether or not they’ve answered the question being asked in the problem.

In Step 4 of Example 3, the discrepancy between the (approximate) solution and the actual time comes from rounding in Step 3.