The "Pi in the Sky" math challenge gives students a chance to take part in recent discoveries and upcoming celestial events, all while using math and pi just like NASA scientists and engineers. In this problem from the 10th set, students use pi to calculate the approximate density of the asteroid (16) Psyche and compare that to the density of known terrestrial materials. Materials Pi in the Sky 10: Metal Math worksheet – download PDF (for best results, download and print from Adobe Reader) Pi i