# subtraction

#### About The Author

##### Michael Goldenberg

I am a mathematics educator with over 30 years' experience teaching mathematics at the elementary, middle school, high school, and community college levels. I have master's degree in mathematics education from the University of Michigan-Ann Arbor. In another lifetime, I earned a master's in English from the University of Florida. I have been field supervisor of secondary mathematics student teachers for the University of Michigan, where I also taught mathematics methods courses to prospective elementary teachers. I've been a math content coach for elementary and secondary in-service teachers in Detroit, Pontiac, Warren, Ypsilanti, and other high-needs districts in Michigan, as well as in New York City. I have a dormant math blog, RationalMathEd, in which I attempted to do some good in sorting out the "Math Wars." I was a founding member of the math education information site, Mathematically Sane. I have a 22-year-old son, Zane, who is studying to be a biomedical engineer, and five rescue cats: Dante, Arya, Athos, Lyra, and Sterling, as well as the scars to prove it. When not teaching, blogging, or stirring the pot, I play a reasonably dangerous game of table tennis.