MathChat

Last days of the school year … kids getting “antsy.”

Harder and harder to keep their attention … so what’s a teacher to do?

Answer:  Let the media help us with the media generation.

In my May 16 post, I pointed you to a website that showed how math is used in major motion pictures.

In this post I’d like to focus on one such reference to math in the movies, and show how you can turn it into a fun “End-of-Year” lesson.

The clip of Die Hard below has a great scene in which the Bruce Willis character needs to solve a mathematical puzzle in less than five minutes to avoid getting blown up. It’s an exciting scene, and the math is interesting.

I suggest that you first have your class watch this clip.

After watching it, review the solution with your class.
In case you had trouble following the fast-talking Bruce, here’s the solution:

— Fill the 5-gallon bucket entirely, and empty the 3-gallon bucket.
— Pour from the 5-gallon bucket to the 3-gallon bucket, fill the 3-gallon bucket.
— The 5-gallon bucket now has just 2 gallons [5 – 3 = 2].
— Empty the 3-gallon bucket.
— Pour the 2 gallons from the 5-gallon bucket into the emptied 3-gallon bucket.
— The 3-gallon bucket now has 2 gallons.
— Fill the 5-gallon bucket entirely.
— Pour from the 5-gallon bucket into the 3-gallon bucket until the 3-gallon bucket it filled.
— You used 1 gallon to fill the 3-gallon bucket to the top, therefore the 5-gallon bucket now contains exactly 4 gallons.
! Solved!

I suggest that you give the same type of challenge to your class. You might want to tell them to imagine that there’s a bomb in the classroom, and they have just five minutes to solve it (if making such an obviously fictional suggestion doesn’t somehow violate school or district policy). Or come up with some other urgent situation. It makes it more exciting.

What follows are some sites that are sources of mathematical riddles you can use for the lesson/activity.

Please RE-TWEET to any teachers who might benefit from this lesson.

Elementary School Level:

Middle School Level:

High School Level: