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Eric Olson Invents Weapon of Math Instruction

Math Department Chair Eric Olson recently released a revolutionary new product to help students better understand and apply the mathematical concept of slope, the Slopometer™.

Slopeometer came about when Eric Olson was teaching curve sketching in calculus. This is when, for example, a graph depicts the position of an object in motion, and you would like to sketch the corresponding graph of the object’s velocity or acceleration of the object. Quickly estimating this can be difficult for a student doing it for the first time—especially when given the graph of the velocity and asked to work backward. While teaching this lesson, Eric said to his class, "Imagine that there is an indicator giving you the slope or instantaneous rate of change of the object: like a plumb bob pointing to a scale with slope values on it that correspond to the instantaneous rate of change.” Thus, a simple teaching aid was born.

Eric stopped by the hardware store on his way home that night to purchase plexiglass, a few nuts, and bolts. He cut out a semicircular piece of the plexiglass, drilled a pivot hole for the arrow pointer, and used a permanent marker to write down as many of the fraction values as he could fit on the scale. Eric’s BC Calculus students greeted the device he jokingly called "Slopeometer" with enthusiasm and encouraged him to patent it on its first day in use. 

Eric says, “I thought it was a bit silly and assumed that somewhere out in cyberspace it must already exist, but I was intrigued enough to look online and found nothing like it. There are lots of clinometers used to measure angles, but I couldn't find anything that used fractions to measure a slope and was intended to be ‘a weapon of math instruction.’” Eric said he would not have pursued the idea without the encouragement of his calculus class, which consisted of Ryan Dreher ’17, Olivia Gracey ’17, Ankur Gupta ’17, Jonathan Jalajas ’17, Max Kelly ’17, Peter Kelly ’17, Ruby Lake ’17, Nina Lubeck ’17, Brendan Parent ’18, Abhijeet Sambangi ’18, Rose Sheehan ’17, Robert Shepard ’17, Reid Smith ’17, Maria Terranova ’17, and Kevin Wheeler ’17. “I owe them a huge shout-out for pushing me to follow up with it,” Eric said.

Later, with considerable help from alumnus Ankur and Technology Teacher Dave Medvitz, who helped Eric to make a very professional-looking prototype using the laser cutter in Pingree’s Makerspace, Eric took the Slopeometer to Didax Educational Resources in Rowley. He also brought along a dozen wooden dice that he used in class to teach the algebraic order of operations (parentheses, exponents, multiplication, division, addition, subtraction, or “PEMDAS”). Didax was intrigued by each idea and chose to develop the math game Eric called PEMdice®. Two years later, Didax published Slopeometer.

Meanwhile, with help from the Pingree Makerspace and Director of Information Systems Bob Ogden, Eric filed a provisional patent application in 2018 and a final application in 2019. It can take three to five years for a patent application to be approved, so it is unclear whether a patent will ultimately be granted, but in the meantime, his idea is protected under the law. Eric has enjoyed using the Slopeometer in other classes, where it has proven useful for teaching concepts covered long before calculus. Didax is marketing it to middle schools where the concept of slope is first learned, and Eric developed several activities around it that are published in a booklet that comes with the device. 

Eric shares, “Throughout the process, I have been able to share Slopeometer’s progress with students, members of DECA, and the Entrepreneurship class. It's not exactly been Shark Tank, but it is a lot of fun to see something get out onto Amazon and into the wider world.”