Appropriate Use of Technology

Walk the Plank

http://www.google.com/url?q=http%3A%2F%2Filluminations.nctm.org%2FLessonDetail.aspx%3Fid%3DL682&sa=D&sntz=1&usg=AFQjCNEXHIXrF9GLee-sZWmiNs55HJme3w

"When one end of a wooden board is placed on a bathroom scale and the other end is suspended on a textbook, students can "walk the plank" and record the weight measurement as their distance from the scale changes. The results are unexpected— the relationship between the weight and distance is linear, and all lines have the same x‑intercept. This investigation leads to a real world occurrence of negative slope, examples of which are often hard to find."  

1. Categories: Learning Objectives, Materials, Instructional Plan, Questions for Students, Assessment Options, Extensions, Teacher Reflection, NCTM Standards and Expectations.

2. Methods and Strategies: This is a hands-on activity using everyday materials.  The teacher holds student interest by using a pirate accent.  

3. Critical Thinking/Problem Solving Observed:  

Why is the slope of the graph negative?

[As the person moved away from the scale, the weight displayed on the scale decreased.]

Why does the weight shown on the scale not accurately reflect your weight?

[The weight shown will be significantly more than your actual weight, because it includes the weight of the plank.]

When a student whose weight was about half of the teacher's walked across the plank, what did you notice about the slope of that student's line on the graph?

[The slope of the line was about half of the teacher's line.]

4. What would I change? The method of assessment is observation and a worksheet.  I would prefer to have students create something more original.  I would have students create something similar to what they would create if they were doing a science experiment. I would relate this to science inquiry (yay for across curriculum teaching). I would have students write about this math "experiment" as they would a science experiment.  What background knowledge do you have?  What is your hypothesis? List the materials procedures, collect and record data, analyze data.