Being our last STEM class before the break, I had students begin to think about the results of our experiment. What has happened so far? Does our compost answer our problem question? Was our hypothesis correct?
We took one more look at our bags of compost and began to list results as of this week. After students came up with some good results, we went up to the field for a few games of Decomposition Tag.
We had the whole class play this fun twist on Freeze Tag. A few students were the character of 'Death' who wore brown string to ID them. We had about 1/5th of the class act as decomposers who wore yellow string. All other students were plants or animals of their choosing. Death could freeze any of the plants or animals. If frozen, a decomposer could run around the frozen plant three times to unfreeze/decompose them. This game has no natural end, but we would stop every so often to have students change roles. This fun P.E. inspired class enforces the idea that life, death and decomposition is a circle. We must have all of the elements for life to continue.
For this class, students reworked their hypothesis and problem/question as we evaluated the compost after one week. This lesson concentrated on the elements of a good experiment and what makes a meaningful question for a science project. We tried to have students isolate one variable with their question in order to create a successful project.
We also checked in on our compost ziplocks. We had students start to identify what was going on in their bags and see what changes had occurred over the week. Most of the compost bags developed a strong stink!
Students who finished their problem and hypothesis came up to the compost bins I set up and tried to find and identify all of the compost critters on our worksheet. They loved finding tiny snails and baby centipedes hiding in the dirt!
This week we had 4th grade students split in half to work on two projects during our hour long segment.
We started a small compost experiment outside on the grass while working on "Dirt for Lunch" inside the classroom.
For our compost experiment, students worked on creating a bag of compost from degradable and non-degradable materials. We filled plastic bags with material as well as soil and proceeded to fill out a scientific method worksheet with our process and predictions. We will check on these bags every week to see what happens.
The students inside worked on our "Dirt for Lunch" project. This traces the students' daily lives to ideas of composting and the source of our food. We had students list everything they ate for lunch then trace it back to the soil. This was a fun project because we had students color large portraits of our food cycle. It is tricky tracing certain things back to soil, like fish, but students worked as a group and came up with some great ideas.
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!