Proportional vs Non-Proportional
- Tom Keeler
- Jan 16
- 1 min read
When is something proportional? This is a little more complicated than it seems.
I get paid $10/hr for babysitting. The amount of money I make is 10 times the number of hours that I work. Proportional! But what about the plumber who charges $150 for showing up and then $100 per hour for labor? This is linear but not proportional. An easy way to tell is if you don't get 0 out when you put 0 in, it can't be proportional. With the 8th graders, we often use the example of a babysitter you like that you give a $5 bonus for showing up and $10 hour. We compare this with the babysitter who eats you out of house and home, whom you charge $5 for the food that will be eaten but also pay $10/hour. 7th graders will start thinking about this difference today.
Thanks for sharing this interesting and proportional learning experience, the more times I read it the more I learned, lol, starting at zero of course. Seriously though, your students are lucky to have you. Thank you!