One of my favorite activities with students is asking them to calculate how many pennies it takes to cover the floor. Take ~20 pennies, a ruler, some string, and go crazy.
There are nice visuals around how many ____ are equal to how many ____ in terms of food. The bacon to cinnabon equivalency is my favorite, I think, because we think of bacon being so unhealthy. (Not that we think of cinnabons as being so unhealthy, but I, as a teenager, was definitely more likely to get a "snack" at the mall of a cinnabon, but would never have gotten a stack of bacon as a snack).
Questions to think about:
-Are all calories the same?
-What sets of 2000 calories can you imagine eating (I can definitely imagine eating 2.5 cinnabons, but not a whole pizza)? How does the mental association of these foods impact your eating?
-These equivalencies represent calories. Which would be the same if we looked at fats/protein/carbs/etc.
-Why is 2000 calories the recommended daily allowance?
Maybe it's not super mathematically interesting, but I do think it gets into units and the meaning of the equals sign in an interesting way.
What is the cheapest way to park for an hour?
What is the most expensive way to park for an hour?
You only have bills, so you ask the nearby store clerk for change. What is the best way for him to give you change for $1 if you want to maximize your parking time? What if the store clerk is running low and doesn't have enough change to give you all coins of the same value?
Is there a systems of inequalities somewhere in here? I can't tell.
