Well, the Algebra students had made catapults out of tongue depressors, rubber bands, and spoons to start out our Quadratic unit a few weeks back. So, when it came to Math 8’s jump in to Data and Measures of Central Variations, I wobbled back and forth…. scoops of M&Ms (previous year’s activity) or accuracy of cotton balls and catapults. Catapults I had to try! Now… should I discuss M.A.D. first, and then let the students do the activity, or Catapults first, and then the discussion?… Well, this year, I went with discussion first. I know… it goes against the the grains of the teaching field these days, but it works for me and the students.

Day 1: Journal foldable and dividers. Kahn Academy notes on Mean Absolute Deviation (because I feel students need to practice taking notes together , recognizing what is needed to be written down, and they don’t always get this from doing it on their own), and story about my days working at Baskin Robbins, and measuring my scoops to get 4 oz right on. Discussion entails onto what other jobs, activities require comparing data to see who is closest in accuracy. (ie baristas, chemists, sports players,…)

Day 2: I had to make sure student knew what catapults are… so we had google slides on this, and the use of catapults (demonstrating with videos from Lord of the Rings or the more humorous Road Runner and Coyote )Students start with class direction page. We sketch out the activity, and then to the Hall! In groups of 2-4, students measure 50 centimeters from the spoon (payload/cup) to the target ( a stickynote with a dot in the center). Then they aim and fling their catapult, recording how far the cotton ball is from the target. They record the number of cm and then go again. Each takes turns for 5 to 10 times depending on the time and continue to record. Then students find their MAD to see who was more consistent during the flings.

Fortunately, our awesome principal came by and asked students what they were measuring. The groups were able to explain the measurements and why they were doing M.A.D. One group’s quote, ” Our numbers are so much better than using the ones already given to you on a worksheet.” Sweet!

Things to remember for next year: More time with this activity ( It should take a full 45 min). Some groups measured the distance the cotton ball flew, instead of how far from the target (which is important to M.A.D. concept). I think a teacher demonstration as well as the sketch will help students grasp it better… but then again, I liked seeing how they set up and started the activity differently. And… next year, prizes for the smallest M.A.D.