In December of 2014, Sony released the movie The Interview online after threats to theaters cancelled the debut in theaters. As originally reported in Wall Street Journal, the sales figures reported in January contained an interesting math problem appropriate for algebra students.
The following January, Sony reported sales of $31 million from the sales and rentals of The Interview. They sold the movies online for $15 and rented through various sites for $6. If there were 4.3 million transactions, how many of the transaction were sales of the movie and how many of the transactions were rentals?
Populations are often described by their doubling times. The doubling time is the amount of time it takes a population to double. We can calculate the doubling time of an increasing exponential model by examining its graph carefully. Since students seem to enjoy themodel for population growth on Gilligan’s Island, I like to use it to illustrate doubling in an exponential function. 
Last week the students in my College Algebra started exponential functions. They got started on the basics of exponential graphs, when they are increasing and decreasing, and exponentials with a base e. With these basics completed, they are working on an Applications Quiz this week. To get them started on this material, I introduced an application based on Gilligan’s Island.
After weeks of linear functions, quadratic functions, and matrices, I needed an introductory example for piecewise functions. Examples like this catch student’s attention and get them thinking about how math might be used in real life. I used the example below in class and in the form you see below for my online classes.