Kids These Days!
The Project:
For more than 15 years, my sixth grade science-teaching colleagues and I have presented a Mag-Lev (Magnetic Levitation) activity to our students at the end of our magnetism unit. This project challenges students to cut a piece of cardboard to fit between parallel aluminum rails. Students select different numbers and varieties of magnets and tape these to the cardboard. The magnets should rest over strips of magnets on the Mag-Lev track so that they repel from the track’s magnets.
This has always been a highly engaging project for students, but each year students seem to struggle with it more and more. Our rubrics have not changed, so we really are comparing “apples to apples”.
Why the Struggle? (Initial Theory):
Why has this activity become more challenging for students each succeeding year? One theory we’ve come up with is that students’ measurement and cutting skills are eroding. So much of today’s world is virtual our reasoning goes (especially for children), that students rarely create things that require measurement or cutting. Choosing proper magnets won’t help if the cardboard pieces don’t fit neatly between the aluminum rails. To test this theory I invented the Cardboard Ski Jumper activity. Careful measurement and cutting of cardboard is its primary focus. The added complexity of the magnets is removed. The Ski Jumper features a pair of parallel wooden rails that angle down at a 45-degrees. On the inside surfaces of these rails are saw-cut grooves. Students must measure the distance between these grooves, and cut a piece of cardboard to fit into them.
This cardboard needs to slide down the Ski Jump without jamming or falling out. As shown in the photograph, there is a wide spot part way down that students must account for.
Students are allowed to use a ruler to measure as many times as they like, but they cannot bring their cardboard to the Ski Jumper unless it is to test it. Grading is as follows:
A: First piece of cardboard slides all the way down the ramp.
B: Second piece of cardboard slides all the way down the ramp.
C: Third piece of cardboard slides all the way down the ramp.
D: More than three pieces of cardboard are cut before one slides all the way down the ramp.
F: No pieces of cardboard are tested in the entire period.
For five years we have been doing this activity, the results have been amazingly consistent—no clear decline in grades. (Approximately 1/3 A’s, 1/3 B’s, and 1/3 C’s and D’s combined.) According to the data, the majority of students can measure and cut cardboard accurately on their first or second attempt.
How Important are these Skills?:
The Cardboard Ski Jumper data indicates measurement and cutting skills are not the main problem during Mag-Levs. On the other hand, many students test multiple Mag-Levs that do not come close to fitting properly between the aluminum rails (I’ll ignore the magnet choices—these are additional problems!). Hmmm.
Two questions: Measurement and cutting. Are these important 21st century skills? How much time should we spend helping middle school students develop these skills? I asked several friends if they regularly use these skills in their occupation. Most told me that accurate cutting wasn’t a commonly used skill, but measurement was. When I pressed for examples of measurement on the job, most gave examples related to hobbies, not occupations. Does this mean careful cutting and accurate measuring are obsolete skills? Is the Mag-Lev an activity worthy of student time and effort? I will sidestep these questions and make a different point. I believe the Mag-Lev activity is less about cutting and measurement and more about something entirely different!
Reflection:
Students must carefully observe what is happening with their Mag-Levs. Is it jammed between the rails? Is it so narrow that it can repel and twist out from between the rails? Are magnets arranged so that one side attracts to the track? Are the cardboard’s magnets right over the track’s magnets? Presented with so many variables, many students become overwhelmed. Their Mag-Lev is not working, but they are unable to identify the problem. They must reflect on their product, and make adjustments. Once adjustments are made, they must again observe and reflect. Such reflection of work is most definitely a 21st century skill. Students may not design Mag-Levs for a living, but they will work on tasks that require their careful reflection. Did I word this memo clearly? Is this the fairest allocation of resources? Did this advertising campaign produce enough additional sales? What is the best design for the bridge in terms of cost, longevity, and aesthetics?
In order to create a successful Mag-Lev, students must carefully observe what is happening with their product and reflect upon their designs. Why does my Mag-Lev appear to attract to the rails even though the rails are aluminum? Why is it always stopping at that spot? Why does my Mag-Lev repel from one side of the track and attract to the other side, even when I flip the magnets over? Authentic practice with reflection, as well as work with cutting and measurement, makes Mag-Levs an absolutely relevant activity for 21st century learners.
But this is not the final word. What do you think?
Here is a video of the Cardboard Ski Jumper.
stithscienceexchange.com 