I went to a Dan Meyer conference expecting a TON of 3 act lesson resources. However, I don't even think that the phrase "3 act lesson" was even said once. Instead I got something better! The math dial. This dial helps you in creating a developing question. So the next day my buddy, Tim McCaffrey, and I started discussing my next lesson, relations and functions. I am working with a text by Springboard. It didn't have a bad idea, but the math dial would increase too quickly if I went straight out of the book. After shooting some ideas back and forth this is what I came up with. (This is the short version. click on document if you would like to see something more detailed.)
-show picture of vending machine and ask what they would get (math dial: 0)
-ask how they would tell machine what they want making sure to use the words input and output during discussion (math dial: 1)
-have them create a menu (most will create a table) (math dial: 2-3)
-showed other representations of relation (code to snack; mapping, table, graph) (math dial: 7-8)
-ask "Would this be a good vending machine if there were two outputs for one input?" (math dial: 6)
-in the end, the good vending machine is a function the bad one is not a function (math dial: 10)
It was fun. There wasn't much math in the beginning of the session, The math dial started at a zero and gradually increased. This is Dan's concept of "developing a question". I love it. Three act lessons are awesome, but they can't be done all of the time and every day. Developing the question can be adapted to almost any lesson and any textbook.
Photos of student menus
Photos of student exit cards
Oh and by the way, the evidence is from an Algebra 1 class full of freshmen who are non-promoters from junior high. I'm pretty stoked with the outcome.