I found a nice little exercise in Mathematics Teaching in the Middle School vol. 19, No. 4, November 2013 called Octane Algebra. It is on the Math for real page aka "When will I ever use this?". The exercise introduces how the octane rating is calculated and what the standard ratings are for types of gas. During the warm-up, I asked "What is Octane?" and several used the iPad to find an answer. I needed to build prior knowledge because out here in the bush of Alaska, most student just buy gas. I do not have a vehicle so I don't buy gas out here. I told the students the next time they fill their snowmachine or 4 wheeler (ATV) look to see what octane rating the gas has. One student told me, it is not there but knowing the young person, they didn't even look.
The worksheet even has them figuring out a range of possibilities based on the fact that the gasoline is a mixture of gasoline and ethanol fuel. The last activity on the sheet has them looking for possible values to produce certain rates and then graphing the results. This is a very nice activity as it has them learning about real world applications for averages.
I am planing on extending this activity to have students research a variety of snowmachines, ATV's, cars, and trucks to see what the recommended octane rating is. Once they have the data, I want them to create infographics, fill out an excel sheet and create graphs. I might even have them create a presentation/video/ etc to share the information. This activity has a lot of potential for literacy and technology.