The fourth grade had a great time last week working with water cohesion and surface tension. The STEM challenge we completed was to see how many drops of water you could drop onto a coin using a pipette without the water spilling over the side. While at first our average was around 35-50 drops, one of our students was able to get over 100 drops onto the surface of a penny. The students really enjoyed this activity and were excited to keep trying. We tried pennies, quarters and a half dollar. We discovered that holding the pipette close to the penny, dropping water on the heads side, and dropping the water slowly worked best.