Since 1995, astronomers have discovered over 100 known exoplanets--planets outside of the solar system--and determined their properties such as mass, orbital distance, size, and density. By using simple algebraic equations of physics, students can determine these properties as well. In this article, the author discusses an activity titled "Wobbling Stars: How Extrasolar Planets are Discovered" that he used in teaching his seventh- through twelfth-grade students. The activity is based on the radial velocity method of planet hunting, Newton's version of Kepler's third law of planetary motion, and the conservation of momentum equation. In this article, the author discusses two methods of planet hunting that he incorporated into the activity, and these are: (1) radial velocity method; and (2) transit method. (Contains 8 figures.)