The Joy of x

I'm an elementary school math teacher, and I picked this up hoping it would give me some good teaching ideas. It's definitely aimed at a higher level than my kiddos, but it's easy to read and made me feel like I could understand higher order math. That's not the same as I understand it, but Strogatz does a good job of simplifying big ideas for laypeople. It's funny, fast, and a good primer/reminder for those of us not using calculus in our daily life.