“My Favorite” was probably my favorite part of #TMC12, literally. The snippets were quick ideas you could easily tweak for your own classroom. So when @misscalcul8 suggested we continue – I was excited. That is until I started thinking about what I would share. How do I pick my favorite? My favorite what? I have a whole list of things I want to share – but today…a favorite unit I’ve used many, many times successfully with my students.
Sadly (for me), with CCSS, we have shifted the ratios/proportions completely to the middle school, so one of my favorite units Who Is Robert Wadlow? is no longer included in our Algebra I curriculum at the high school. I would leave students with the question at the end of class the day before beginning the unit “Who is Robert Wadlow?” Several would go home and look up – find information. The following day, we would discuss, share his measurements (most in metric units) and as a class we would determine how to convert to standard units – so it would make the most since to our American Brains. So my question – was he unnatural? Or just a bigger version of us? If you research, you’ll see how he was normal size baby when he was born. We talk about how you go to the doctor for well-child visits and they measure you – plotting your height/weight on “that curve” and discuss why doctors do that. How if we’re growing too fast/slow the doctors can run tests to see if something in our growth hormones need to be modified…
Anyway, to end the day we all measure our foot lengths and heights and create a scatterplot…surprised to see – its somewhat correlated (yes 9th graders are growing, so its not perfectly linear…) – then we add RW’s (ft, ht) to the plot…again, surprised to see, he fits the pattern…just a bigger version. We calculate the height/foot length ratios for the class, then split the data out to boys and girls to see if there is indeed a common ratio…once again, surprised to see how close the ratios actually are. We talk about people who are clumsy in while growing – what their ratios would look like – if they are too tall for their feet, etc.
I shoudl note I used this as opportunity to teach students how to enter data into lists on TI-84, L1=foot length, L2=height, L3 = (L2/L1) and how to create scatterplots on graphing calculator.
One year I even had students ask if this was related to Vertruvian Man and explore if they were similar to him.
As a final project in this unit, I would assign Super Size It as part of their unit assessment.
Y, B, H with their Super Size It projects.
Special K – scale factor of 5 …125 times more cereal!
Extra Gum – scale factor of 3 … 27 times more gum!
Chocolate Pudding – scale factor of 2 …8 times more pudding!
You could easily modify this activity to fit high school geometry – to determine how scale factors affect surface area / volume ratios.
Robert Wadlow Ratios & Proportions Unit Organizer
A few other files I have used within this unit –
- NLVM Unit Conversions Website
- Lake Holattawatta – capture/release
- Spoonful of Sugar – ratios open response
- Doctor’s Office – Direct Variation
- PTO-Fundraiser Inverse Variation
- Tree House – Indirect Measurement
So, for My Favorite Friday – one of my favorite units – I no longer get to use – hopefully one of you can use an idea or two and keep the spirit of Robert Wadlow & Super Size It alive!
the radical rational... 