Section 11 - "Probability"

You can use the TI-81 or TI-82 calculators to generate random numbers. They can simulate the roll of one die, two dice and three dice by using one, two or three calculators. This activity will allow you to simulate the rolling of dice, which makes for a "quieter" class. (And you won't have to hunt for the dice!)

ACTIVITY:

Enter the following program into your calculator. This program will generate the random numbers from 1 to 6. The program is:

Int(6*Rand+1)

To enter the command do the following:

Press MATH
Move your arrow down to Int and press ENTER.

(You should see Int on your screen.)

Now press "(" and type in "6" and "*".

Press MATH
You should be on Rand. Press ENTER.

Now press "+" and "1" and ")"

Press enter about four or five times to see what happens. Describe below.

1) Now, you will "roll" your die by pressing enter. You will create a by recording the number of times each number 1 through 6 comes up. Roll your die 50 times. Record the number of times each number comes up by using tally marks. Before you start write down the number you think will come up most often. _______.

1

2

3

4

5

6

What were the results? _____________________. Were you right? _____________ .Why or why not? Describe below.

2) Next, you will break into pairs and "roll" two dice. Each of you will press enter and record the sum of the numbers on the calculators below. Roll your dice a total of twenty times. What sum do you think will occur most often?______. Go ahead and roll your dice and record your results below.

What sum(s) came up the most? ______ Why? __________________________.What sum(s) came up the least?______Why?___________________________________. Create a chart of all the possible outcomes below.

3) Finally, break into groups of three and "roll" three dice. This time you will play a game using the three dice and determine whether or not it is fair. You will all press enter at the same time. Person A will get a point if all three numbers on the calculators are the same. Person B will get a point if all three numbers are different. Person C will get a point if two numbers are the same. Keep track of your points below.

I am person ______. Score -

Did you win?________. Why or why not?_________________________________. Would you consider this a fair game? Explain below why or why not below. Also, show all of the possible outcomes below.