Guesstimation

Have been browsing Guesstimation: Solving the World's Problems on the Back of a Cocktail Napkin by Lawrence Weinstein and John A. Adam for a few weeks now. I was pleased when I saw the local high school including instruction in some of these style techniques. They did not go far enough, but it was a noble effort. It's all about estimating solutions to problems. I remember being fascinated by these methods when I learned scientific notation in school. That added to just a bit of clever thought, can solve some very tough problems. You can see excellent archived examples at the Guesstimation site.

You can solve tough problems without calculator or computers, a joy for the quant in us. A slight criticism is that they should have used more meaningful illustrations to help the visual thinker. A bit related, but different: How to Measure Anything: Finding the Value of "Intangibles" in Business by Douglas W. Hubbard. On my list.