Understand patterns, relations, and functions

• identify functions as linear or nonlinear and contrast their properties from tables, graphs, or equations.

• use symbolic algebra to represent situations and to solve problems, especially those that involve linear relationships;
• recognize and generate equivalent forms for simple algebraic expressions and solve linear equations

• model and solve contextualized problems using various representations, such as graphs, tables, and equations.

• use graphs to analyze the nature of changes in quantities in linear relationships.

• Understand such attributes as length, area, weight, volume, and size of angle and select the appropriate type of unit for measuring each attribute
• Understand the need for measuring with standard units and become familiar with standard units in the customary and metric systems.

• Develop strategies for estimating the perimeters, areas, and volumes of irregular shapes.
• Select and apply appropriate standard units and tools to measure length, area, volume, weight, time, temperature, and the size of angles.

• Technological:
  Students must be able to:
  • perform basic mouse manipulations such as point, click and drag.
  • use a browser such as Netscape for experimenting with the activities.

• Gather population information.
• Prepare 1 egg bungee harness for demonstration.

• Access to a browser
• Access to Microsoft Excel
• 50 equally sized rubber bands
• A 4 inch by 4 inch piece of cloth
• 4 paper clips
• 1 meter stick
• 1 tray
• 4 eggs

1. Focus and Review
• Review prior estimation activities.
• Review Microsoft Excel basics.
2. Objectives
Students will acquire knowledge about and demonstrate how to estimate using a trend line.


3. Guided Practice
• Have the students open Microsoft Excel.
• Have the students enter in some population data the teacher provides for the years 1790 to 1830.
• Have the students predict the population for the year 2000 using a trend line.
• Have the students predict the population for the year 2050
• Have the students enter in some more population data the teacher provides for the years 1840 to 1920.
• Have the students predict the population for the year 2000 using a trend line.
• Have the students predict the population for the year 2050.
• Question the students:
  • Which prediction do you think is better?
  • Why?
  • Has our data changed?

4. Teacher Input
• Provide the students with the actual population data for the year 2000.
• Explain the difference in projection accuracy made by having more data points.
• Describe the procedure for data collection on the egg bungee experiment.

5. Independent Practice
• Have students begin data collection for egg bungee.
• Have students enter their information into Microsoft Excel.
• Have students create a trend line (Excel's line of best fit) and predict how many rubber bands it will take to get their egg as close to the ground as possible without breaking when it is dropped from a predetermined height.
• As a class have the students take turns dropping their eggs from a predetermined platform. (A stairwell will work well for this.)

6. Closure
• Discuss how the number of data points affects the trend line.
• Discuss some of the variables that cause deviance from the trend line predictions.
• Review results.
• Discuss some real life applications of this type of estimation.