How many matches must be played to determine a tennis tournament champion? This problem is one of Stella's Stunners, a collection of challenging and entertaining mathematical problems to intrigue students in grades 6 - 12. The Stella problems are ideal for promoting inquiry, problem solving, and classroom discussion of key mathematical ideas. Sample solutions are provided for each problem, but students may find other solutions and may even compete with their classmates to find the most creative solution path. Stella problems can be printed out individually or in sets designed for Pre-Algebra, Algebra I, Geometry, Algebra II/Trigonometry, or Pre-Calculus. Problems can be printed with or without solutions and can be added to ORC Collections. The Stella website includes a wealth of teaching resource materials, including an essay on the value of problem solving, a list of 25 useful problem-solving heuristics, a biography of Stella, several tips for using Stella problems in the classroom, and listings of the Stella library by course, by title, and by Stella number. ORC hopes you enjoy the Stella problems, and we invite you to share with Stella's author any experiences you have using Stella problems with your students. (Stella number 1180.65)(author/sw)