How much is Domino’s really charging for pizza?
My thoughts on Domino Effect: http://fivetwelvethirteen.wordpress.com/2014/10/23/dominos-and-linear-equations/
I completed this lesson with my advanced Algebra I students as a preview for what we will be doing with linear equations. They seemed to enjoy working with pizza. Some students struggled with finding the cost of a single topping of pizza. The common mistake was adding the cost of both the medium pizzas then dividing by the total toppings of both pizzas. I also like to present this with using Domino's actual website and building their own pizzas. I had to find the zip code for Mathalicious because if I used my communities zip code the cost is too easy to figure out, 1.00 per topping. When doing this I found that Domino's has changed their cost per topping in the DC area, so watch out for that if you have the kids build class pizzas. It also nice for students to see that there is a limit to the number of toppings and price saturation limit.
Thanks for sharing your experience, Joseph. Were you able to help students realize the flaw in their approach to finding the cost per topping?
I used this as a refresher on linear functions for my advanced 8th graders in Algebra I. They really liked it. I decided to hold off on using the terms slope and y-intercept (even though they were applying the concepts). We used mini-whiteboards for Act One. Next up will be the iCost lesson (although I can't seem to find it anymore on the site.)
Hey Matt -- You're right that iCost is missing! When we transitioned to the shiny new site, there were some lessons that didn't make the cut. BUT there are some other great linear lessons on the site. Have you checked out Not So Fast? (And if you really need iCost, email holler@mathalicious and we'll explain how to get the old slides.)
Thanks for sharing your thoughts on Domino. We almost never mention slope and y-intercept when using this lesson. We don't need to -- we're just talking about pizzas! Of course, later it's helpful to reference the cheese pizza when we talk about y-intercept and topping price when we talk slope.
What have other folks done? Do you let Domino live in a math-term-free space and introduce formal vocab later? Or do you mention the formal language as you go?
#6 on the student guide contains the wrong graph. It is the graph of the cost of two medium pizzas; it should be the graph of how much Domino's actually charges. The lesson guide contains the correct graph.
Thank you for this observation. I could not figure out what #6 was asking until I saw your note. (This is my first time using this resource so I didn't understand the disconnect between the lesson and the handout.)
Nice lesson overall. I would extend the lesson to recognize the range and domain of each function (equation).
For sure! That's a great deeper understanding question...and one you can explore pretty richly in the final question.
Nice overall. Could use a repeat button on the first page movie.
@Paul - Thanks for the notes! You can play the video on the first page again by pressing play again.
loved this! just wish all the equations were in slope-intercept form
@Debra -- Thanks for the note. We carefully chose write the equations that best matched the scenario. In this case, the way we talk about pizza pricing is generally something like "A medium pizza's $10.99, plus $1.49 per topping." Students can -- and should -- write the equation in the way that makes the most sense to them. And, from there, a teacher can opt to have an additional discussion about form.
I will be using this lesson with High School Algebra 1 students. I cant wait to see the level of engagement. I will post feedback.