id: 06211013 dt: j an: 2013f.00483 au: Mooney, Edward S. (ed.); Bair, Sherry L. (ed.) ti: Penny drop. so: Math. Teach. Middle Sch. 18, No. 3, 136-139 (2012). py: 2012 pu: National Council of Teachers of Mathematics (NCTM), Reston, VA la: EN cc: G33 K53 ut: circles; area; grade 8; frequency table; probability; games; experimental mathematics; discovery learning; student activities; problem solving strategies; experience reports ci: li: doi:10.5951/mathteacmiddscho.18.3.0136 http://www.nctm.org/publications/article.aspx?id=34491 ab: From the text: Studentsâ€™ thinking is discussed, and the procedures used with problem solving are explored. The penny drop problem appeared in [the editors, ibid. 17, No. 6, 319 (2012)]. To play the penny drop game, drop a penny from a height of 4 inches over a target. If more than the half of the penny is inside the circle labeled 50, you score 50 points. You need to add a 25-point region to the target so that the probability of scoring 25 points is double the probability of scoring 50 points. Experiment dropping pennies from a 4-inch height on your new target and record your results. Once you have decided on a region or regions, write an explanation of how and why you chose that area. A diagram was provided to illustrate the size and position of the 50-point circle on a board. Additionally, two full-size templates were available online for teacher use, one with a background grid and one without a grid. Teachers were encouraged to choose the template they believed was more appropriate for their students. Colleen Donahue, an eighth-grade teacher, sent in her studentsâ€™ work and shared some reflections. These reflections provided wonderful insight into not only studentsâ€™ thinking but also how a teacher presented the task and how it was used in the classroom. rv: