Math Teachers at Play #29 via The Number Warrior

After a slight delay, the new Math Teachers at Play carnival is up at The Number Warrior, with a nice variety of blog posts to browse. Enjoy!

Math Teachers at Play #29 The last time I hosted Math Teachers at Play I attempted to start a tradition of including a math puzzle pertinent to the number of the carnival. Alas, it didn't take, but now that I'm hosting again I can mention an old classic: Three people check into a hotel. They pay $30 to the manager and go to their room. The manager finds out that the room rate is $25 and gives $5 to the bellboy to return. On the way to the room the bellboy reasons that $5 … Read More

via The Number Warrior

MathCounts: Grandfather Clause for Existing Homeschool Teams

Click here for the official update. Small schools are not mentioned, but it seems logical that their existing teams would also be grandfathered in. Maybe? and according to Mathmom’s comment below, small schools are left out in the cold.

… After taking all concerns into account, a compromise was crafted that would grandfather in homeschools and virtual schools that participated in the 2009-2010 program year to allow them to participate on teams in this year’s Competition Program. All new homeschool and virtual school participants must abide by the new eligibility rules that require those participants to register only as individuals. This compromise was brought to the MATHCOUNTS Board of Directors and approved unanimously.

Therefore, for the 2010-2011 school year, all homeschool and virtual school groups that registered for the MATHCOUNTS Competition Program either as teams OR individuals during the 2009-2010 program year will be allowed to register teams or as individuals for the upcoming 2010-2011 program year, following all of the 2009-2010 requirements for participation.

MathCounts: No More Homeschool Teams

MATHCOUNTSIf you’ve heard rumors about the new ruling, here is the official take.

I try to avoid ranting on this blog, but I’m deeply disappointed. My students always enjoyed the team aspect of working/suffering together. I don’t know if any of them will be willing to participate as individuals.

Update: MathCounts: Grandfather Clause for Existing Homeschool Teams

How to Start an Argument: The Monty Hall Problem


[Photo by MontyPython.]

You can get a good argument going in almost any group of people with the infamous Monty Hall problem:

Imagine you are on a TV game show, and the host lets you choose between three closed doors. One of the doors hides a fancy sports car, and if you pick that door, you win the car.

You pick door #1.

The host opens door #3 to reveal a goat. Then he gives you a chance to switch your door for the unopened door #2.

Should you switch?

What if you say you’re going to switch, and then the host offers to give you $5,000 instead of whatever is behind door #2?

Try the game for yourself at the Stay or Switch website.

Continue reading How to Start an Argument: The Monty Hall Problem

Math Clubs, Math Circles, and the Richmond Math Salon

Photo by jaaron via flickr.

If you’ve been thinking of starting a math club, here’s a good model:

People have this notion that math is about getting a right answer, and the testing really emphasizes that notion. And that’s such a bad way to approach math because it makes it scary.

When you look at little kids, they pose their own questions. They say, “Ooooh, what’s bigger than a million?” And they think about things their own way. At school, the teacher poses the questions, and the students answer their questions. Schooling is not a natural environment for learning.

— Sue VanHattum, Math Mama Writes
Richmond Math Salon: A Sweet Sampling

Continue reading Math Clubs, Math Circles, and the Richmond Math Salon

Math History Tidbits: The Battling Bernoullis

July 27th is Alex’s birthday. She shares it with Johann Bernoulli, an irascible mathematician from the late 17th century. This coincidence intrigued her enough that she wrote a research paper on Johann and his mathematical brother, titled “Jeering Jacob and Jealous Johann.”

Of course, to make the alliteration work, she had to mispronounce Johann’s name — but she figured he kinda deserved that. Read the historical tidbits below to find out why one writer said the Bernoulli brothers were “the kind of people who give arrogance a bad name.”*

Continue reading Math History Tidbits: The Battling Bernoullis

Probability Issue: Hints and Answers

Remember the Math Adventurer’s Rule: Figure it out for yourself! Whenever I give a problem in an Alexandria Jones story, I will try to post the answer soon afterward. But don’t peek! If I tell you the answer, you miss out on the fun of solving the puzzle. So if you haven’t worked these problems yet, go back to the original posts. If you’re stuck, read the hints. Then go back and try again. Figure them out for yourself — and then check the answers just to prove that you got them right.

This post offers hints and answers to puzzles from these blog posts:

Continue reading Probability Issue: Hints and Answers