Water Measurement

Our second and third graders have been learning about water in our science unit. We have learned where water is found on earth, how we use water at home, and where we get the water that we use in our homes. This past week, we began to think about how much water is on the earth and how we could conserve water each and every day. We began this new thought with a globe activity which had students throwing a plastic globe to each other as they stood in a circle. Students passed the globe 25 times and as the students caught the globe, they would state whether their left thumb landed on water or land. I kept a tally on the board marking how many times students had their left thumb on water or on land. After passing it 25 times, students sat down and I calculated our results.

The results should have shown that approximately 75% of the earth is covered in water, however our results showed about 60%. We then discussed how this "globe throw" wasn't an exact science; if we had time we would do what scientists always do and conduct this activity multiple times to discover a more accurate answer. 

The following day, we discussed how liquids can be measured. We talked about how, at home while cooking, we can measure liquids using measuring cups or teaspoons and tablespoons. We also discussed how scientists usually measure liquids a bit differently, using graduated cylinders which measure liquids according to milliliters. Students discussed how scientists want their measurements to be accurate and exact, so they should always set their graduated cylinders on a flat surface to discover the number that is closest to the real measurement. To give students an idea of how scientists measure, students were placed in groups and given water and a graduated cylinder to practice measuring accurately. In these groups, students took turns pouring water into the graduated cylinders and trying to make their measurement as exact as possible. Students enjoyed having this opportunity to act as scientists and make these accurate measurements. 

After this activity, students were given a homework assignment where they were to measure how much water they use while brushing their teeth with the water running and with the water turned off. I can't wait to see the results of these homework assignments and to begin discussing water conservation!