 Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum  MENU          Session 5, Part B:
Slope (40 minutes)

In This Part: Thinking About Slope | Comparing Slopes | Slopes and Architecture

 Slope is an important concept in mathematics, and in Part B we'll explore how it is used to solve problems. Note 5  Problem B1 Take a minute to think about what you already know about slope. What does it mean? Where is it used? You may be familiar with the idea of slope as a measure of steepness. The formula for slope is usually described as slope = (change in y) / (change in x) The slope of a line is often described as a ratio of rise/run. Another way to think of slope is as the amount that the dependent variable changes for each increase by 1 in the independent variable. In other words, as x changes by 1, what happens to y? The following Interactive Activity explores the concept of slope. Measuring slope requires two points. As you work with the examples in the Interactive Activity, ask yourself why the slope between pairs of points would change or why it would stay the same. Note 6 This activity requires the Flash plug-in, which you can download for free from Macromedia's Web site. If you prefer, you can view the low-tech version of this acivity, which doesn't require the Flash plug-in. Problem B2 What happened when you tried to find the ratio of rise/run for the fourth example in the Interactive Activity, a curved object? Problem B3 The drawing below shows a cable attached to a wall. Calculate the ratio rise/run for each pair of points:
Note 7

 • Points P and Q • Points P and R • Points Q and R Problem B4 Describe the difference between the rise/run ratios for the graph in Problem B3 and the ratios for the graph of a line. Note 8

 Problem B3 taken from IMPACT Mathematics Course 3, developed by Education Development Center, Inc. (New York: Glencoe/McGraw-Hill, 2000), p. 26. www.glencoe.com/sec/math   Session 5: Index | Notes | Solutions | Video

© Annenberg Foundation 2017. All rights reserved. Legal Policy