Welcome to my math blog! The purpose of this blog is to help you stay informed about our learning and experiences that have taken place during our math class. I have also included links your child (and you) may want to use in order to supplement math learning in 5th grade.

Thursday, February 6, 2014

Probability: Dice Dilemma

We began our last part of probability today....
working with dice.

I began the class by reading the book "Jumanji," by Chris val Allsburg, to my students.  The story is about two children who begin a board game, discover that the game becomes real, and must finish the game to return things to normal.  At the pinnacle of the book, Judy must roll a 12 in order to win and, therefore, end the game.  At this point, I paused and explained that we were going to explore the probability of Judy rolling a 12, before finishing the story (there was much groaning to have to wait!).

To begin, we needed to list all the possible outcomes of rolling two dice.  To watch the process of finding all possible outcomes, please watch the video:  Dice Dilemma, part 1.

Once we listed all of the possible outcomes, we were able to determine the probability of Judy rolling a 12 into a fraction.  There is only one possible way to roll a 12 out of 36 possible combinations.  Therefore, the fraction was 1/36 and it was determined that it would be very unlikely that Judy would roll a 12.  To find out what happened in the story.... we finished the book!

Now it was time to turn our data into theoretical probability (what SHOULD happen).  We first listed all of the events that could happen when rolling two dice (sums from 2-12).  Then we listed the number of ways each of these sums could occur. Next, we used fractions to describe the theoretical probability, turned the fractions into decimals using calculators, and converted our decimals into percentages.  To watch the process, please watch the video:  Dice Dilemma, part 2.

Finally, it was time to experiment!  I gave each student a pair of dice.  They rolled their dice 50 times and kept a tally of each sum rolled.  I combined all of the data into a spreadsheet for each class.  Then we used the totals to find our experimental probability as a percentage.  The circled percentages are the percentages that worked out exactly as our theoretical probability said they would.

4 matches with theoretical probability

5 matches with theoretical probability

8 matches with theoretical probability

Tomorrow, we will combine all of the data from the three classes to see if our theoretical probability and our experimental probability compared.

HOMEWORK:  Countdown 3.8