## Tuesday, May 20, 2014

### Day 25 of 30: Ven Diasel in The Fast & The Refreshing

This is Day 25 of the 30-day blogging challenge. Almost done and nearly out of horse-racing metaphors as we pull away in the homestretch!

There's a shop in school where some of the students run things (supervised by staff, of course). I want to be clear that I'm not talking about the school store that sells notebooks, gym clothes and hoodies, and general school spirit items. No, this one has coffee, snacks, bagels, fruit, pizza and cold beverages.

I stopped in during my lunch period for a cup of coffee (half-decaf, it was late in the day and I didn't want to finish off the pot of regular, nor ask them to make another pot, which would've been mostly wasted). As I'm prepping my coffee, another staff member comes in and tasks the women by the counter with this challenge: I need something cold to drink that's sugar-free, no caffeine and not carbonated. (And not water.) She had to stop and think about it and look over to the refrigerator.

And I thought to myself: Wait! I can do this! I'm a MATH TEACHER!

Stand back! This looks like a job for Venn Diagrams!

If we make three circles, one for caffeine, one for sugar and one for water, we can place items in these circles and see what doesn't have a home! What is the complement to the union in the Universal Set that is the Refrigerator?!

Now, there is a slight problem in that you can't have a four-circle Venn diagram. However, the fourth set was "Water" and the only element contained in that set would be "Water", so we'll leave that aside and deal with it later. Basically, the top ten choices fall into the Venn diagram as follows:

As you can see, I came to the realization that the most suitable beverage was "Sugar-free Lemonade". However, as I was on the other side of the room by the coffee maker, I had no clue if that was an option. However, given the varieties of flavored iced tea drinks from a company that also has fruity drinks, it seemed like a logical bet. If not, I'm sure that they found a suitable sugar-free fruit-flavored drink in among all the bottles.

What did I find? Another problem to torture my students with!

I wonder if Venn diagrams are part of the Common Core?