March 26, 2010 by Uri.

Patterns come in all sizes and shapes, delighting our senses. Here is one pattern that entertains the ear, the eye and the sense of rhythm.

Posted in rhthym, Math Fun, Patterns, Math | No Comments »

March 10, 2010 by Uri.

A customer walked into our auto-parts store looking for a flat washer. “That’ll be 15 cents,” I said.

“Fifteen cents for a washer? Are you crazy?” he yelled. “I’ll drill a hole in a quarter and make my own.”

Jack Reeves

[Source: Reader’s Digest, August 2009, @Work (p. 67)]

Posted in Jokes, Reader's Digest, Math Fun, Math Humor | No Comments »

February 22, 2010 by Uri.

In her YouTube video, Amelia entertains us by turning her body with dance into a mathematical visual aid. She also demonstrate the endless ways one can present mathematical concepts.

Posted in Math Dance, Math Fun, Math Video, Math Learning, Math | No Comments »

February 22, 2010 by Uri.

Driving is a serious matter but this is funny.

Visiting family in Kentucky is a heart-stopping experience if only because my brother-in-law drives in the middle of the road, straddling the double
yellow lines that separate traffic. My sister-in-law does little to ease my fears. Seeing the horror in my eyes, she once said, “Don’t worry. Everyone around here drives in the middles of the road.”

Lisa Walters, Ypsilanti, Michigan

[Source: Reader’s Digest, June 2009, Life (p. 198)]

Posted in Jokes, Reader's Digest, Math Humor | No Comments »

October 21, 2009 by Uri.

Who would ever want to have 10,000 left shoes?

Well, here is a story that has stuck in my head for many years. I may be off on the specifics but I believe the just of it is true. And, if not, it could have happened or, in storytelling parlance, it’s plausible.

As I recall, in the mid 1960’s in Israel I read in the paper that a shipment of 10,000 left shoes had arrived in the port of Haifa from Italy. At the time, custom duty rates in Israel were extremely high, especially on such luxury imports. So the importer did not claim the shoes. Besides, what would he do with 10,000 left shoes? Stuck with this load, the custom office did what most custom agencies do with abandoned stuff, it auctioned it off. But no one had any use for 10,000 left shoes so no one made any bid. Well, eventually the original importer made a very low bid and the custom office was happy to get rid of the shoes that took space in its warehouse. So the importer got his 10,000 left shoes practically paying no duty.

A month or two later a shipment of 10,000 right shoes arrived in the port of Haifa and the same importer did not claim them because he did not want to pay the duty…

Surely, you have figured out by now the rest of the story.

Where is the math in this story?

It has to do with sets and how sets can be split, added up and rearranged. A pair of shoes is a set, a very useful set. It can be sold. 10,000 pairs is a set of 10,000 such useful sets. Splitting these pairs into 10,000 left shoes and 10,000 right shoes generates 2 sets containing 10,000 of useless shoes, which no one wants to buy. But then, whoever has both sets can recombine them to form the original 10,000 sets of sellable pairs of shoes.

Posted in Sets, Math Reasoning | No Comments »

December 27, 2007 by Uri.

Is it always true that if you have a good thing, then having more of it is better and, conversely, if you got something bad having more of it is worse? Case in point, consider the following situation (usually told as a joke):
“What is worse than finding a worm in the apple you are eating?”
“I don’t know… Two worms.”
“No. Half a worm!”

Posted in Math Humor, Fractions, Numbers | No Comments »

December 20, 2007 by Uri.

I am always amazed at the ingenuity of the human mind. I’ve always been interested in and even fascinated by knots and tying. I’ve known several ways of tying shoelaces and did not give it much thought. I considered it so simple, once it was tied, the shoelace knot is one of the most basic knots. nothing to it.

Wrong!

Several years ago, when my son was in first grade I was awed by one of his classmates, a second grader, when I saw how she tied her shoelaces in a single, fluid motion. I asked her to repeat it and she did but her fingers always moved too fast for my eyes to catch the details of her action. The result, however, was the familiar knot. She told me that this is the only way she knew to tie her laces.

Then I came across this video and I learned how to tie my shoelaces in the same way.

It’s not difficult and you can do it too and fascinate your friends.

Posted in Topology, Math | No Comments »

October 28, 2007 by Uri.

In her Math Doesn’t Suck: How to Survive Middle-School Math Without Losing Your Mind or Breaking a Nail, Danica McKellar writes in a language that will appeal to her target reader — middle-school girls. It is a commendable attempt to encourage girls to do well in their math studies. Danica presents middle-school math subjects in context that is relevant to the girls she addresses. I hope she is most successful.

I have found one problem with the book, a publishing problem, and I wish that Hudson Street Press, the publisher, will fix it for the next edition. The problem is this:

If a girl or someone who loves her is shopping at Borders or Barnes & Noble store, they would probably browse the Young Adult section, perhaps even the Young Adult Nonfiction shelves. Unfortunately Math Doesn’t Suck can be found only in the math section of brick and mortar or online bookstores.

I suspect that the culprit is the classification of the book as “Mathematics—Study and Teaching, Middle School” (see the back side of the title page.) Before its next edition, paperback — I’m certain it will have one — or otherwise comes out, Hudson Street Press should also list this title under something like “Young Adults, Girls Life”. I am suggesting this not because the book deserves this classification, which it does, but more importantly, girls and anyone, who cares for them, should be able to come across it without having to mistakenly wonder into the math section of the store.

Posted in Math Books, Math Education | 1 Comment »