Thursday, April 30, 2009

Probability with Spinners

We are are learning basic probability in second grade. To start off, I used a big die on the Smartboard and we tallied which number the die landed on. Then I gave them their own dice and they played. Then we got to spinners. The spinner in Notebook is pretty cool. It is very easy to change the number of sections and to change the colors of the sections. I changed things and each time we talked about most likely color and least likely color. We had fun doing that. When we were finally ready to make predictions and then try it out the students wanted 8 sections on the spinner. They decided to have 5 red and 3 green. Then they had to predict how many times it would land on red. There would be 19 spins (the number of children that day) so many of them predicted it would be red 12-16 times. Of course, probability never works neatly when we want it to. Green ended up winning by 1. I had to convince them that we did make good predictions, but we were not guaranteed. We did not have time for the whole class to take another round of turns, so while they were working on a math book page, I sat and ran the game again. The students kept an eye on the Smartboard and the tallies while they worked. This time, red won. I was quite relieved.
I don't have a lesson file for this because we made the changes as we went a long. Of course I forgot to take a screen shot of our tallies and fractions, but I do have a picture of the spinner.


Joseph Miller said...


That is cool. I bet they were psyched when you were playing. Of course, the key with probability is the more times you run the test the closer to the prediction. How do you think students would better understand that if you had done the spinner 1000 times instead of 19 it would have worked out a lot neater?

Lisa Kellogg said...

Students would absolutely have a better understanding that the more times we do it, the closer to our predictions we would get. It would be great if I could run an applet to spin it and record it while we worked on something else. Actually, we could keep it going in the background and regularly spin it ourselves and tally the results. Something to think about.