When cake is 20, pie is 5. When cake is 100, pie is 85. So pie = cake – 15, or p = c -15.

• the sense of humor to say “I want to whisper the function in your ear because I’m too lazy to do the math.”

• the honesty to say “I want to whisper the function in your ear because I need...

This photo tells half the story of today’s Math Circle: people working together to solve a problem. The question was whether the famous “Gas Water Electricity" problem is solvable or impossible...

“I’ve got it!” said X, J, M, N, A, G, and D.  Almost everyone came up to the board (excitedly and without invitation) to demonstrate a solution to the famous...

“We got those for Christmas,” announced G as she arrived and saw the Polydrons scattered across the table. “They were the only educational thing we got.”

 A brief flash of worry...

“Well, we don’t want to waste erasers here in Alexandria, so this is the best method,” argued R (playing the role of Euclid), after she demonstrated how to perpendicularly bisect a line with only...

Photos of a Julia Set crop circle and a Cissbury Ring crop circle whetted our appetites for circles this week. Everyone had many questions about how the crop circles got there, particularly how...

Michaelangelo, Bernini, Lloyd Wright (or, the students wondered, was it simply Wright?), Zarah Hussein, Native American geometry designs, mapmakers art, the feng shui compass, and a photo of a...

The green tape on the rug hinted at a quadrilateral shape, but was actually composed of 4 line segments that did not meet at corners. Is it safe to say that the lines would definitely meet and...

On the rug, the children sat around a green tape square which enclosed some toy cars, office supplies, a plastic dog, a book, and other sundry items. I explained that in our continuing zoo story...

We began this week’s math circle sitting in an ogre - not a circle, not an oval, but an ogre, as suggested by the kids. This used the math skill of mentally shifting from the concrete to the...