This is a guest post by Kathryn Laster, who teaches math in a suburb of Dallas, TX. She writes: This year was my 20th year of teaching, so my humble opinions qualify as part B of your "call for guest bloggers." I really started working on my formal philosophy as a grad school assignment, and I have been slowly tweaking it for several years. Since this was a milestone year for me, I thought it would be appropriate to really re-think and re-visit my philosophy, and your call for guests inspired me to do so. My brief resume: this year, I taught ESL algebra 1, pre-calculus, and AP calculus AB, and this is also my 10th