Clay Bond was a faculty member in the Penn State Smeal College of Business who was also a blogger who sometimes wrote on math education. He passed away recently after a battle with cancer, and some of his work is being remembered on the blog kitchen table math, the sequel. In “I Would Like an Answer Now” he demands accountability from high school math teachers for the failings he sees in his college students. Here’s part of it:
Me: “Can I erase this?” I pointed to the whiteboard, and he nodded. I erased the curve, and wrote a series of numbers on the board in a vertical column: 90, 85, 70, 65, and 50. “These are test scores,” I said, “How do you calcualate the mean, or average?”
Mark didn’t volunteer an answer.
Me: “Okay, let’s say the whole class takes an exam, and these are the scores. An average, or mean, tells me how well the class did overall. To calculate the average, I add all the scores, then divide by the number of scores. Here, you do it.” I have him the marker.
Mark added the numbers, then stopped.
Me: “How many scores are there?”
Mark: “Five.”
Me: “Okay, divide the total by five.”
Mark complied.
Me: “What’s the mean?”
Mark: “Seventy-two.” He looked at the numbers for a minute, then smiled. “I get it!” he said.
That’s when I realized what I’d suspected: Mark was a university freshman who had not, until just now, understood the concept of an average.
