As students use the manipulatives in activities, they will need to collect enough data to analyze. In most projects, students should work with at lease one partner to ensure data is as accurate as possible. Allow students to account for human error. As humans, it is nearly impossible to measure anything with 100% accuracy. For this reason, we also generally use three trials and find an average. If our activity were to find the area of the average hand towel, students would need to measure at least three different brands and find an average. This ensures that our measurements are as close to the mean as possible. For the example activity, students drop Barbie three times per additional rubber band, and measure the lengths of the falls in centimeters. Students then find an average and convert to inches.
Once data is collected, students should find an appropriate method of display. Some data lends itself better to bar graphs or pie charts while other data is better represented in a line graph. We look to the type of data to know the right display to choose.
When we collect data that represents parts of a whole, pie charts are the best means to display the information.
When we have data that shows various numbers with no relation to each other, we are more likely to choose a bar, picture, graph.
When the data we collect has some relation, we can showcase the information best with a line graph, or continuous graph.
In 8th grade, students work with linear equations. These equations demonstrate the pattern that occurs with a constant rate of change. The example Barbie project emphasizes linear equations and graphs because of the constant rate at which Barbie's fall changes with each additional rubber band.
For more information on creating graphs, check out this powerpoint.