Perimeter Mapping

I have been conducting a problem of the each (POW) each week in my one-day-a-week class and it's realized some evolutionary success over time.  Today I had my students work on a project that had them first estimating then measuring the perimeter of our school.

Part 1: Estimation

I began with my students in small groups (3-4) mapping out the plans of our school.  They then had to estimate what the total perimeter might be.  Guesses ranged from 17m to 470m.  I was a little shocked by the range of responses.  It just shows me that the concept of larger perimeters is somewhat nebulous in the mind of an intermediate student.  The initial sketches weren't bad though they seemed to be a little off with some of the distances.

Part 2: Field Work Estimation

The title for this section isn't the greatest, but it makes sense.  Once I showed them the length of a metre, I sent the groups outside to estimate the school's perimeter.  Students estimated using arm spans and were pretty creative with the ways they measured the distances.  Some worked well in little groups while others just following a single, counting group member.  At the end they came up with a more realistic range of 240m to 580m.  Though this was an improvement the range still was pretty large.

Part 3: Digital Measuring

For the following class, we spent some time with Daft Logic's Distance Calculator to obtain a more precise perimeter measurement.  With the exception of a few outliers, the results were pretty consistent.

Conclusion
To wrap up the lesson and take work in for assessment, I had my students write a short report (the basis for the table above) which included the first and second estimation plus the digital animal with a screen capture (see image above) for evidence.   They were brilliant!

Reflections

• Assign specific tasks to each group member when measuring the perimeter
• Allow time to debrief any findings