Most textbooks present logarithms as just one more set of mechanical procedures to be memorized and repeatedly applied. Their history of how and why they were invented, however, is rarely presented. In addition, all too often the common sense proofs of the basic properties of logarithms are not emphasized at all. James Tanton, a research mathematician-turned-teacher, presents a quick, rigorous, yet interesting way of teaching logarithms in his take on logarithms essay [PDF]. Like many of his essays, this one contains links to videos on the subject for those who prefer to watch rather than read. If you’re a teacher this will make your lesson preparation easier.