I have struggled for years with the science experiment part of the LEGO WeDo Drumming Monkey robot. The experiment workshop tells the students to write down “What I see or hear.” Without further instruction, second grade students tend to write things like, “Da da da da da.” Even though that is a description of what they heard, it does not at all capture the relationship between the position of the cam gears and the drumming patterns. So, for years, I tried to get the students focus on the frequency and pattern of the beats. This worked better but the second grade teacher and I were still not satisfied with the results. She suggested a more systematic approach to writing down the patterns but the first and fourth rows (see below) are really the same pattern without a reference to an actual beat such as 30 beats/minute.
She found a good iPad metronome app that has an option to count 1, 2, 3, 4. I came up with a modified worksheet that will allow the students to precisely describe the patterns. This also related directly to what the music teacher is teaching them. We have not tried it yet but we are excited to see what happens next week.
It is interesting how long it can take for solutions to these teaching problems to occur.
Note that if you mentally superimpose the left and right cams and envision them going around, it is easy to see how it works. However, this formal operation would not be available for students until they were entering adolescence.