Let’s Play Math!

Entries categorized as ‘History’

Euclid’s Geometric Algebra

July 7, 2008 · 1 Comment

Picture from MacTutor Archives.

After the Pythagorean crisis with the square root of two, Greek mathematicians tried to avoid working with numbers. Instead, the Greeks used geometry to demonstrate mathematical concepts. A line can be drawn any length, so straight lines became a sort of non-algebraic variable.

You can see an example of this in The Pythagorean Proof, where Alexandria Jones represented the sides of her triangle by the letters a and b. These sides may be any length. The sizes of the squares will change with the triangle sides, but the relationship a^2 + b^2 = c^2 is always true for every right triangle.

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Categories: Alexandria Jones · Algebra & beyond · History
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Math History on the Internet

June 27, 2008 · 6 Comments

[Image from the MacTutor Archive.]

The story of mathematics is the story of interesting people. What a shame it is that our children see only the dry remains of these people’s passion. By learning math history, our students will see how men and women wrestled with concepts, made mistakes, argued with each other, and gradually developed the knowledge we today take for granted.

In a previous article, I recommended books that you may find at your local library or be able to order through inter-library loan. Now, let me introduce you to the wealth of math history resources on the Internet.

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Categories: History · Mathematics · Uncategorized
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Hooray for (Math) History

June 19, 2008 · 13 Comments


Photo by Benimoto.

John Napier foiled a thief with the aid of logic and a black rooster. For this and other acts of creative problem solving, his servants and neighbors suspected him of witchcraft.

What does this have to do with mathematics?

Math was Napier’s favorite hobby. He invented logarithms to help people handle large numbers easily, and he even created a calculator out of a chessboard. [See how it works: addition, subtraction, multiplication.]

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Categories: History · Mathematics
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An Ancient Mathematical Crisis

May 27, 2008 · 7 Comments

funny pictures

[When Alexandria Jones and her family visited an excavation in southern Italy, they learned several tidbits about the ancient school of mathematics and philosophy founded by Pythagoras. Here is Alex's favorite story.]

It hit the Pythagorean Brotherhood like an earthquake, a crisis of faith which shook the foundations of their universe. Some say Pythagoras himself made the dread discovery, others blame Hippasus of Metapontum.

Something certainly did happen with Hippasus. The Brotherhood sent him into exile for insubordination, or for breaking the rule of secrecy — or was it for proving the unthinkable? According to legend, Hippasus drowned at sea, but was it a mere shipwreck or the wrath of the gods? Some say the irate Pythagoreans threw him overboard…

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Categories: Alexandria Jones · Algebra & beyond · History
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Alexandria’s Dog is Now a Teacher

May 25, 2008 · 2 Comments


Photo by alex-s.

A reader of Indian descent has been kind enough to write to me about a difference in our cultures. In the US, or at least in the parts with which I am familiar, it is common to name one’s pet after a famous person. In India, however, to name a dog after a human is a very deep insult.

I am sorry! It was not intended that way.

Therefore, I have re-named Alexandria Jones’s dog after a Westerner. I would like to keep the tradition of naming the characters in my Alex stories after people in math history, so I am hoping this one will not offend anyone.

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Categories: Alexandria Jones · History
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The Puzzling Pythagorean Pebbles

April 12, 2008 · No Comments

Italian ruins
Photo by meichimite.

Alexandria Jones and her family flew to Italy for spring break. Her father, the famous archaeologist, had to visit an excavation.

It was late when their plane landed in Crotone, a small coastal city near the instep of Italy’s boot. Dr. Jones had used the Internet to find a hotel that allowed pets, so Alex was able to snuggle down with her favorite pillow — her trusty dog, Ramus.

The original school of mathematics

The next day, Dr. Jones introduced his family to Sonya Theano, a former student of his and the director of this dig. “Come, let me show you around,” Dr. Theano said. “We’ve uncovered several buildings of a small compound, set apart from the city of Crotona, as it was called then. From the pottery and trade goods, we estimate these buildings were in use around 550-500 BCE.”

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Categories: Alexandria Jones · History
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Happy Pi Day, 2008!

March 14, 2008 · 8 Comments

funny pictures

Now there is an ancient Greek letter,
And I think no other is better.
It isn’t too tall,
It might look very small,
But its digits, they go on forever.

— Scott
at Mrs. Mitchell’s Virtual School

Time to celebrate

Are your students doing anything special for \pi Day? After two months with no significant break, we are going stir crazy. We need a day off — and what better way could we spend it than to play math all afternoon?

If you need ideas, here are some great \pi pages:

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Categories: Activities · Algebra & beyond · Grades 5+up · History · Middle elementary
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The Secret of Egyptian Fractions

February 5, 2008 · 7 Comments

Egypt’s Great Pyramid
Photo from Library of Congress via pingnews.

Archaeology professor Dr. Fibonacci Jones came home from a long day of lecturing and office work. Stepping inside the front door, he held up a shiny silver disk.

“Ta-da!” he said.

“All right!” said his daughter Alexandria. “The photos are here.”

They had to chase Alex’s brother Leon off the computer so they could view the images on the CD, but that wasn’t hard. He wanted to see the artifacts, too. Alex recognized several of the items they had dug up from the Egyptian scribe’s burial plot: the wooden palette, some clay pots, and of course the embalmed body.

Then came several close-up pictures of writing on papyrus.

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Categories: Alexandria Jones · History
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Rewriting the History of Math

October 22, 2007 · No Comments

Here are a couple of quick links to math in the news:

MathTrek: A Prayer for Archimedes
It turns out Archimedes was even closer to discovering calculus than we had thought.

Tales of the golem: With many cheerful facts about the square of the hypotenuse
While Pythagoras, on the other hand, sees his place in math history threatened by an experimental disproof of the Pythagorean Theorem. [Hat tip: jd2718.]


Related Posts:

Categories: History · Math Humor
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A Very Short History of Mathematics

August 30, 2007 · 1 Comment

This paper was read to the Adams Society (St. John’s College Mathematical Society) at their 25th anniversary dinner, Michaelmas Term, 1948. [Warning: Do not attempt to read this while drinking coffee or other spittable beverage!]

Hat tip: I found this through the math carnival at a mispelt bog.

Related Posts: more math humor

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Egyptian Geometry and Other Challenges

August 24, 2007 · 4 Comments

Rhind papyrus

Would you like to study “the knowledge of all existing things and all obscure secrets”? That is how Scribe Ahmose (also translated Ahmes) described his mathematical papyrus. Ahmose’s masterpiece is now called the Rhind Papyrus, after Alexander Henry Rhind, a Scotsman who was one of the first archaeologists to make meticulous records of his excavations (rather than simply hunting for treasures). Rhind purchased the papyrus from an antiquities dealer in Luxor, Egypt, in 1858.

Ahmose’s writing included a huge table of fractions as well as story problems, geometry, algebra, and accounting. Can you solve any of Scribe Ahmose’s problems?

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Categories: Alexandria Jones · History
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Egyptian Math Puzzles

August 11, 2007 · 1 Comment

Pyramids clip artWhat we know about ancient Egyptian mathematics comes primarily from two papyri, the first one written around 1850 BC. Moscow papyrus problem 14This is called the Moscow papyrus, because it now belongs to Moscow’s Pushkin Museum of Fine Arts. The scroll contains 25 problems, mostly practical examples of various calculations. Problem 14, which finds the volume of a frustrum (a pyramid with its top cut off), is often cited by mathematicians as the most impressive Egyptian pyramid of all.

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