A terrific piece by Paul Lockhart. This was originally published in 2002 and is 25 pages long. It's an excellent critique of all that is wrong with K-12 mathematics education, and articulates why I have been banging my head against a wall regarding my 8th grader.
But I don't want to go there.
If you care about math, education, or why mathematics is more like art than science, give it a read.