Sometimes a picture says it all. The tweet below and some extrapolation on your students part would be a really nice introduction to exponential functions.
You should probably also talk about reliability of sources. Even in math class.
This Logarithm War Game is another one from Kate Nowak. It’s played just like that card game you used to play when you were 8, only to determine whose card wins, students will have to quickly evaluate a logarithm. Kate says the kids love it. I believe her.
The cards you need to print and cut out are available at the link above.
Dan Anderson describes an activity he did with his class to analyze the true interest rate of the rent-to-own scheme used by many stores. Teachers could easily find similar ads for local merchants to bring this activity closer to home for their students. I tagged this activity as a learning activity and problem solving. It is probably both.