2-7: Additional Problem Solving

Part 1

Intro

A bar diagram is a model that you can use to represent part-to-whole relationships. Consider the following situation:

A company has 5 samples to ship to a client. Each sample has the same weight. A box to ship them weighs 8 ounces before it is packed. The total weight of the shipment is 47 ounces.

You can make a bar diagram to represent this situation. Let g represent the weight of one sample.

A bar diagram: Total weight = g + g + g + g + g + weight of the box, or 5g + 8 = 47.

So you can represent this situation with the equation 5g + 8 = 47.

Example Using Bar Diagrams for Two-Step Equations

You and your friend play online video games. You buy 1 software package and 3 months of game play. Your friend buys 1 software package and 2 months of game play. Each software package costs $20. The total cost is $115. Make a bar diagram to find the cost of one month of game play.

Solution

Let x = the cost of one month of game play.

A bar diagram: 115 = x + x+ x + 20 + x + x + 20.

The equation is 115 = 5x + 40.


End ofPage 83

Table of Contents

Digits, Grade 7, Volume 1, Homework Helper Unit A: Number and Operations Unit B: Expressions, Equations, and Relationships Unit C: Measurement and Geometry Unit D: Proportionality English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties