Implementing the “Professional Standards for Teaching Mathematics”: “The Farther Out You Go…”: Assessment in the Classroom
I can thank a student named Billy for teaching me about the importance of integrating assessment with instruction. It was the early 1970s, and I was teaching in an alternative high school that I had helped found the year before, in a converted warehouse in central St. Louis. Our students were drawn from the city's school-dropout population, and many had not been in a mathematics classroom for years. Luckily, our classes were relatively small, which permitted me on this day to reflect on what Billy had done on a task. I had put five decimals, all between 0 and 1, on the chalkboard and asked the class to rank them in order of number size—a list something Like .06, .607, .6, .6707, .067. Billy anayed them in descending order of length, longest to shortest. I asked, “Which is the number with the smallest value, Billy?” He pointed without hesitation to .6707. “How come?” I asked. This time, Billy thought a bit and seemed to be looking at what he had done through the mists of school memory. “I don“t know. I sort of remember one of my teachers saying, ‘The farther out you go in a decimal, the smaller the number.’”