This lesson went really well. The students generated good hypotheses as to why some things float and others sink. At first, they thought that all the small things would sink because they were choosing only small metal items such as the keys and the metal nuts. After they made that statement, I presented them with a very tiny piece of the Styrofoam and asked them what they thought would happen to it. They predicted it, too, would sink, but after they were proved wrong, they began to create a new theory. I asked them how the Styrofoam was different than the other objects and they stated that they were made out of different things. They realized that all the wooden objects would float. They hypothesized that all metal things sink and that anything that has a lot of air inside, such as balloons and hollow plastic items, would float. Using their own hypothesis they were able to correctly predict which items would sink and which ones would float.
The students were very engaged in the lesson. They were very excited to be able to put things into the water to see what would happen to them. It was easy to see the joy on their faces when they proved themselves right after predicting whether an object would sink or float. I gave them lots of positive praise along the way so even if they predicted incorrectly, no one became discouraged. I made sure each child had a chance to choose an object to place into the water. They each had a chance to make a prediction about an object before it went in. I believe this lesson worked so well because it was done with a small group. If I was doing this lesson with an entire class, I would want to have the class split up into small groups with each group having its own container of water and similar objects. This way all the students get the opportunity to explore the objects and get a turn to put them into the water. This keeps everyone engaged.
One of the things I realized about designing the lesson was coming up with questions to ask. While it was simple to come up with a basic outline of how the lesson would go, many of the questions I asked the students were based on how they were responding to what I was presenting them with. Their comments and observations spurred more questions that I would not have necessarily anticipated asking them prior to implementing the lesson.
Things I would change about the lesson would be using a bigger container of water. It began to get crowded with the objects after awhile, but since I did not wish to take objects out, it became difficult to see the effects of some of the items. Also, I think instead of putting the chart on a transparency, I would just make a big board chart with the pictures on it. Since there were so many items, the chart had to be split up onto multiple transparencies and it was time consuming to switch from one to another if we referred back to an object we already did. Another thing I would probably change would be to give the students the pictures already cut out or give them the ones we tested already cut out and just allow them to cut out the ones we did not test. I would make this change because I noticed that many of the students were still at the stage where they had a lot of difficulty manipulating scissors. They took more time cutting than they did trying to decipher which side of the paper the picture should go on. While practicing motor skills is important, I did not want it to be the focus of the lesson.
Below are samples of the students' work. I decided to post these two because of the discrepancy of where the bowling ball picture was pasted. One student said it would sink because it was heavy but another said it would float because it had a lot of air in it. In retrospection, I should have chosen pictures of objects that I could bring into the room so that after the students predicted what would happen to them we could have tested those objects out, too.
