IPS - Day 11

Today focused on practicing using the probability concepts and skills that have been developed. We started off by trying to construct a Venn diagram for the Sounding the Alarm problem that we had worked on previously. I like re-visiting problems as it helps students make connections and build knowledge bridges.

Students typically struggle with this as their inclination is to have on circle represent one alarm sounding, a second circle to represent two alarm sounding, and the intersection to represent three alarms sounding. They don't feel entirely comfortable with the representation but it seems to fit. Some questioning as to what distinguishes Alarm 1 from sounding versus Alarm 2 makes them realize that haven't accounted for this aspect of the problem. The next question I pose is whether two circles is enough to represent the situation?

One student actually came up with the idea of using 3 circles on his own. After discussing with the class the merits and deficiencies of various representations I had this student present his solution. The class could readily see how three overlapping circles represents the events of different alarms sounding.

We then spent the rest of the period working through a variety of problems that focused on representing problems through tables and Venn diagrams, calculating different probabilities based upon addition, and dealing with terminology, such as mutually exclusive, and symbolic representations for "and" and "or."

We'll continue practicing calculating probabilities next class. This is all in preparation for working with conditional probability and looking at the idea of independence.

Visit the class summary to read a student's perspective of the class.