Pi Day Coloring Activity: Pi Skyline. Create your own round version of Pi Cityscape to make a mural, door decoration, or bulletin board display. Let your students express themselves using these hands-on Math & Art resources during the exploration of Pi.Write the next digits of Pi in the sections outside the circle. Mark the height of the bars using the ruler provided so that each bar corresponds to one digit of Pi.Then color the bars to create a round city skyline (colored/black/rainbow).