Loved that Lesson Linky - Combinations and the Lottery

A great fellow blogger - Meg Anderson from The Teacher Studio - invited me to participate in this linkup from her blog.

This is a great idea, and I hope you follow along to check out all of the ideas :)

One of my favorite lessons that always generates a ton of interest is a lesson on Combinations in Algebra 2 or Precalculus.

I start the lesson by placing a $50 bill on my desk.

As the students start to enter the room I tell them - someone in the room is going to have a chance to win this $50 today during class.  Students are really excited…who doesn't love money?

In Illinois, we have a lottery where people choose 5 numbers from 1 to 40.  If they choose the correct 5 numbers, they win big money - like millions of dollars!

The seniors in my class are old enough to buy tickets and AHEM - win, so I want to show them how unlikely it is that they will win.

You can make this fit any lottery situation, but I have the students pick 5 numbers from 1 to 40.  They must write them down in pen in their notebook. (FYI - in my lottery the order the numbers are chosen in doesn't matter.)

Before I begin choosing numbers, I have all the students stand up.

I use my projector and my TI-Nspire calculator to randomly generate a number between 1 and 40.  I am sure to project this to increase excitement.

After the first random number comes up on my calculator, I have all of the students sit down who do not have that number in their list.  I hear disappointed sighs from the class.

Then I generate a second random number and again have the students who do not also have that number on their list sit down.

At this point, I usually have MAYBE one student left standing and everyone is rooting for them.  I generate the third number and unless that student has that number too, by now everyone is sitting down.
(In 25 years of teaching, I have never had a student get more than three numbers correct, and that only happened twice.)

After all the students are sitting, I generally hear a lot of "Let's play again!"  I generally play 4 or 5 times before I get down to the reason we are playing the lottery in class.

This lesson really seems to motivate the students and they are all interested in their chances of actually winning!