We’re into this unit again with the freshmen. Teaching a course the second time around is a joy. I have a much better idea of what difficulties they’re going to have. What mistakes they’re going to make. What the misconceptions will be. More importantly, I can catch them earlier, either by changing the activities I did last year or by changing the discussions that surround each activity.1
We’ve been collecting data:
How long is five seconds?2
I started this one by asking, “Who’s really good at judging how much time has passed without looking at your cell phone?”
I had a stopwatch, told them I’d say “start” and they had to tell me when 5 seconds had passed. First person timed at 3.6 seconds. Lots of “I can do better!” type comments were shouted. We did a few more as a class, then they were off to collect five trials for each person. Collected the data. Made a histogram. Discussed the data (mean, median, mode, range, outliers, symmetry … you get the idea).
What’s your stride?
They were sent home to measure their stride length – from the front of one foot to the front of the next. Instructions included to explain how they measured this.
This one was fun to discuss the next day. One student used the boards on her hardwood floor. She marked her steps on the floor, counted the slats, and measured the width of one slat and used that to estimate her stride length. Another student walked on the snow on her sidewalk and measured the footprints. I thought the best part of the discussion was figuring out which measurements didn’t make sense. 32 inches? Nope, this person measured two steps. 12 inches? This person measured from toe to heel. 11 inches? Turns out that really was his stride length. 8 inches? The dog’s stride length.3
1The little notes I wrote last year in the teacher’s guide are like presents from a former self.
2Supplies: Graph paper and a stop watch for every two people. This is the ideal. Or you could let them use their cell phones, if phones are allowed in your school that is.
3Okay, this one actually happened last year. I miss that kid.
