This week we started our STEM class with an introduction to the scientific method. This is going to be an important concept throughout the year for 4th grade and especially within the STEM class and our learning based project.
I started class with a small experiment. I brought in a tennis ball and then asked the class whether it would bounce higher on carpet or tile. I began the experiment by dropping the tennis ball on the tile from waist height. I then threw the ball down very hard against the carpet causing it to bounce very high.
For the second try I bounced the ball with a low angle and spin along the tile floor. For the carpet, I threw the ball high in the air underhanded. It bounced higher off the carpet.
On the third try I let the ball drop on the tile from above my head. On the carpet, I released the ball about an inch from the ground. The ball bounced higher off the tile.
From this experiment I deduced that a tennis ball will bounce higher off of carpet. The class agreed that although true for our experiment, this assumption is not correct because we changed the experiment every time. This led us into the scientific method. We must first plan an accurate experiment into order to get good results. This includes the concept of a constant: everything stays the same; and a variable: one thing to change.
After this we filled out a worksheet outlining the steps to a more accurate experiment that includes a constant and only one variable. The variable would be the floor.
After this students came to the front of the room bounced the ball from the same height for three tries, and measured the ball's height with rulers. We then deduced that a tennis ball bounces slightly higher off the tile than the carpet.
We then moved on to the PB&J exercise. I had students list steps on the board on how to make a PB& J sandwich from the materials I brought in. With their instructions, I ended up putting unopened jars of peanut butter and jelly on top of a bag of unopened bread. Yummy. After this we went through the exact steps of the experiment in order to show the detail of the process. Usually when doing an experiment, the process should be the longest and most intensive part of the write up. When we finally got the sandwich ready, the last step was to feed it to the worms in the compost pile. Yummy!