The team at **Mathalicious** has totally figured out “the hook.” My kids were completely hooked on their “Domino Effect” lesson the minute I showed the opening video snippet which demonstrates how to order a pizza from the Dominos website. My honors students immediately wanted to go to the Domino’s website themselves to play around with the ordering process, to see how many toppings they could order and if they could split toppings, etc. One of my on-level students asked how much trouble he would be in if he actually placed an order and it was delivered to our school. Regardless of level, they all had questions and wanted to investigate the ordering process themselves.

We first went through Act 1 and Act 2 of the Mathalicious lesson, and the kids did a GREAT job calculating the cost per topping, and then graphing the data and writing an equation for a medium pizza. Over half of the students ran with the lesson and did the same for the small and large pizzas while I was helping one weaker group. When I showed them the actual graphs, students had a great discussion about the pricing model.

“If you put too many toppings on, the pizza won’t cook all the way through.”

“You’d have to put less pepperoni on if you were going to add a bunch of other toppings.”

“I wonder if all pizza places limit you to 10 toppings.”

“I think they should charge more for 5 because you could squeeze in a 5th topping without cutting back on the first four.”

Who knew I had so many pizza experts?

During our next class we moved on to the Mathalicious “Chain Gain” extension lesson. The night before I had posted a poll on Edmodo and kids voted on their favorite pizza places (our local Bottom’s Up came in first and new restaurant Twisted Tomato tied for second). They reviewed the results of the poll and then chose two restaurants to explore to determine pricing for small, medium and large pizzas (they could choose restaurants that were not on the list as well). To save instructional time, I created a Google Spreadsheet as a template for them to record their data (we are just moving over to Google Docs so they have only used Google Spreadsheet one other time).

We ran out of time quickly so came back later in the week to do some more research. We narrowed the research to just one restaurant because of time constraints. Students discovered the Papa John’s website gives a discount when you order a 2nd pizza, so you must empty the cart completely before calculating the price for each number of toppings. I’m not gonna lie here – I was just a little bit nervous with one of my classes that Papa John’s might just show up in the front office with a pizza, for their class, but luckily that did NOT happen. Sadly, Bottom’s Up was blocked from school (a student did tell me you have to be careful when googling that at home ha ha) so students had the choice of picking a restaurant that was not blocked or doing the research at home. One of the students found a local restaurant who offers gluten-free pizza and she was thrilled. Some pizza places only offer small and large pizzas, and one offers small, large and x-large, so students had a good discussion on how to compare sizes if they do not fit into the standard small, medium, and large categories.

Back in class we talked about their findings, and how to best include this information in a presentation. I showed them how to use Desmos to graph their data (they had already determined the equations based on the number of toppings). We talked about how to take screen shots of the spreadsheet and the graph, and how to include those in a Google Presentation. We had a great class discussion about what should be included in a presentation about their toppings and we developed a rubric for the presentation.

Integrating Desmos provided the opportunity for a discussion on how to restrict the domain and range of a graph, as many of the restaurants limit the number of toppings. Mathalicious+Desmos=Magic. The discussion about limiting Domain alone made this project worth the instructional time! I feel like the students totally got WHY the domain could be restricted, and how to use Desmos’s restriction feature to make their graph match their data. It just doesn’t get any cooler than that. Here are some sample projects – I am **thrilled** with how this lesson went!!

Example with limited domain and pricing maxed out with 4 toppings

Example with limited domain and pricing for specialty toppings shown separately

Example without limited domain or pricing