Factorial Fun

Today my IB juniors were learning about factorials.  (As a reminder: 5! is read as "5 factorial" and means 5 * 4 * 3 * 2 * 1.)  Several said that they loved the exclamation points because it made the math more exciting.  For the rest of the period whenever the answer called for a factorial they would shout the number to account for the exclamation point.  So 10!/5! would be "TEN divided by FIVE."  As their hilarity grew it got a little difficult to tell the difference between "TEN" and "ten" but I have to agree that it did make for an exciting class.

Tomorrow they want to learn math that uses question marks...I think that means we're going to be inventing something.

New Record

I may have set a personal record for number of absences in one period.  My first period on Friday was missing 10 out of 25 students!  No, we haven't been hit with an epidemic of swine flu - I think that only one student was sick.  The others were seniors who were helping on the 3-day junior retreat, helping at the soup kitchen (a group of 10 seniors goes every Friday), or going on college visits.  This sort of absenteeism is so typical for our school that I've decided not to bother giving tests or quizzes on Fridays if I can possibly avoid it - it's just not worth dealing with all of the makeups.

Down to Two

My three person senior IB class has shrunk again - now we are down to two!  In some ways this class is a dream come true - two highly motivated, very gifted students who will tackle any problem that I throw at them.  Unfortunately I'm rather rusty on the advanced math, so trying to find some interesting problems that supplement the curriculum is proving to be a challenge.

We're zipping through the curriculum, so last Friday we took a break and spent the period figuring out winning strategies for various simple games, including Nim and a variation of tic-tac-toe.  (In a simple variation of Nim, two players take turns taking 1 or 2 stones from a pile of 20 stones.  The last person to take a stone wins.)  Unfortunately my students decided that now that they know how to force a win in each of these games, they can start hustling people!  They may be my only students who see how what I teach them actually applies to real life!

Laugh of the Day

From first period study hall...

Me: Why aren't you doing any work?
Student: I left my backpack in the hall during the assembly and someone stole it.
Me: Really??? [Kids leave their stuff all over the place at our school and theft is very rare.]
Student goes out in the hall and returns in about 20 seconds with her backpack.
Student: I didn't see my backpack the first time because my sweatshirt was on top of it.

Trivia Fridays

Three times a week we meet for 10 minutes in the middle of the day in small community (basically a homeroom).  Considering that our classes are 85 minutes long and lunch is only 25 minutes, I think having this extra break for students to talk with friends is a good idea.  However, other than reading announcements that my community of seniors couldn't care less about, there isn't much to do during that time.  So this year I instituted Trivia Fridays using the new response card system that the school purchased for each department.  I type up the multiple choice questions in powerpoint and then students use the "clickers" to record their answers.  The computer keeps track of the points for each student.  It's a fairly nice system and the students love it, but somehow I don't think when the administrators spent however much on this system that they envisioned it being used to play games.  Hey, at least it's being used!

The Allure of an Empty Water Jug

Last year one of my students brought one of these empty water cooler jugs to class.  There was no good reason for it - apparently he just found it somewhere and couldn't resist picking it up.  I had to confiscate it because of course it was a major distraction.  Over the course of the day students tried to use it as a drum, a kazoo, a bat, and, my personal favorite, a telescope.  I, on the other hand, saw the tremendous mathematical possibilities in it and since that day have dreamed of my students using geometry and calculus to verify that it really does hold five gallons of water.  Today my dream came true!  After starting with an angled water glass and moving on to a wine goblet, my senior IB students used volumes of rotation to calculate the volume of the container, taking into account the cutout for the handle.  It was a truly beautiful sight!

The Verdict is In

The Precalculus students took their first full-length test on Thursday.  Testing weeks are full of a roller coaster of emotions for me - typically depression and stress the day before followed by hopeful anticipation during the test and then either joy or deeper depression after grading them.  To illustrate, here is what I was going to post on Wednesday:

School gets out at 2:45.  I was there until 4:45 today helping Precalculus students prepare for the test tomorrow.  I should be feeling good that so many students cared so much about learning the material.  Instead I feel like a failure because I know that several of those students will need a miracle to pass the test.  I don't like it when any of my students fail but I hate it when a student works hard and still can't do it.  I know that they have accumulated deficits from 12 years of math education.  I know that at least one has documented memory problems.  I know that several of them should not have waited until the day before the test to come in for help.  But I still believe that if a student sees me for extra help, I ought to be able to get him to pass the test.  When I look at the grade distribution on this test last year, I can't believe that I was able to help the students do that well.  There is no way that the majority will get A's and B's tomorrow.

Well, today I graded the tests and the verdict is...joy! Unbelievably my students actually did better this year.  I had about the same number of A's and B's but far fewer D's and F's.  One of the students who I thought would fail got a respectable 65%, almost double his score on the last test!  I am so proud of them!