Skit: The Handshake Problem

[Feature photo above by Tobias Wolter (CC-BY-SA-3.0) via Wikimedia Commons.]

If seven people meet at a party, and each person shakes the hand of everyone else exactly once, how many handshakes are there in all?

In general, if n people meet and shake hands all around, how many handshakes will there be?

Our homeschool co-op held an end-of-semester assembly. Each class was supposed to demonstrate something they had learned. I threatened to hand out a ten question pop quiz on integer arithmetic, but instead my pre-algebra students presented this skit. You may adjust the script to fit the available number of players.

Continue reading Skit: The Handshake Problem

Happy Pi Day I

photo by jorel314 (cc by 2.0)
photo by jorel314 (cc by 2.0)

It can be of no practical use to know that Pi is irrational, but if we can know, it surely would be intolerable not to know.

Edward Titchmarsh

I don’t remember anyone ever mentioning Pi Day when I was in school, but any excuse to celebrate math sounds like fun. March 14 at 1:59 (a.m. or p.m.) is about as close as the calendar can get to 3.14159…

Continue reading Happy Pi Day I

In Honor of the Standardized Testing Season…

[Feature photo above by Alberto G. (CC-BY-SA-2.0) via flickr.]

The school experience makes a tremendous difference in a child’s learning. Which of the following students would you rather be?

I continued to do arithmetic with my father, passing proudly through fractions to decimals. I eventually arrived at the point where so many cows ate so much grass, and tanks filled with water in so many hours. I found it quite enthralling.

— Agatha Christie
An Autobiography


“Can you do Addition?” the White Queen asked. “What’s one and one and one and one and one and one and one and one and one and one?”

“I don’t know,” said Alice. “I lost count.”

“She can’t do Addition,” the Red Queen interrupted. “Can you do Subtraction? Take nine from eight.”

“Nine from eight I can’t, you know,” Alice replied very readily: “but—”

“She can’t do Subtraction,” said the White Queen. “Can you do Division? Divide a loaf by a knife — what’s the answer to that?”

“I suppose—” Alice was beginning, but the Red Queen answered for her. “Bread-and-butter, of course.”

“She can’t do sums a bit!” the Queens said together, with great emphasis.

— Lewis Carroll
Through the Looking Glass

…in other words…

If you could lead through testing, the U.S. would lead the world in all education categories. When are people going to understand you don’t fatten your lambs by weighing them?

Jonathan Kozol
at Westfield State College’s 157th Commencement

Continue reading In Honor of the Standardized Testing Season…

Math Carnival #2

Carnival of MathematicsThe math geeks have hit the town at the Second Carnival of Mathematics, which features a wide variety of articles to enjoy—many of which are admittedly over my head.

I liked these:

Puzzle: Is the spider hungry?

My Favourite Theorems 1 (Halting Problem)

The results are in!

It’s been a very busy few weeks, and I never got around to posting last week’s carnivals. Here are a couple of math-related posts from last week’s Carnival of Homeschooling:

How the four operations become two

Words of Wisdom from Reader’s Digest

And from the Carnival of Education:

Testing Higher Order Thinking Skills — Part Two

Mind Over Math — Believing It Makes It So