Topic: Geometry

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Bicycle Math


You are brought to a crime scene. You are told that a thief just made off with a bag full of diamonds, escaping on a bicycle. You come across a pair of bicycle tracks in the snow, no doubt made by the fleeing thief. But which way did the thief go? Just by looking at the shapes of the tracks, can you determine which way the thieving cyclist went: left to right or right to left?

Grid Power


“When I grew up in the Soviet Union, all we used for math was grid paper. Grid paper leads to discovery.” This is how Tatiana Shubin, San Jose State University, begins her lesson demonstrating the myriad of wonderful math questions arising from a simple sheet of grid paper. Attempting to count all squares of any size on a limited grid will require participants to persevere, organize their thinking and construct viable arguments.

Folding Perfect Thirds


Imagine you’re packing for a trip, and you’re planning on bringing your favorite tie. It’s too long to fit in your suitcase, even after folding it in half. You would fold it into fourths, but you don’t want all of those creases ruining your tie. You’ve decided folding it into thirds will be the perfect length to fit in your suitcase without noticeable creases on your tie. However, you don’t have a ruler or any means of making sure your tie is folded into perfect thirds. Is there anything you can do about this?

Mondrian Art Puzzles


You’re Mondrian’s mathematical boss. Instead of allowing Mondrian to randomly draw rectangles and colors -you lay out requirements: 1) Mondrian must cover an N by N canvas entirely with rectangles. 2) Every rectangle in the painting must have different dimensions. 3) Mondrian must use as few colors as possible, and rectangles with the same color cannot touch one another.

Under these rules, Mondrian must try to minimize his score. A painting’s score is the area of its largest rectangle minus the area of its smallest rectangle.

Queen’s Move


Students will explore a game between two players moving a chess Queen from place to place on a square grid. The Queen may move any number of spaces to the left, any number of spaces downward, and any number of spaces on the downward-left pointing diagonal. Each player takes turns using these moves. Whoever gets the Queen to the bottom-left square first wins!

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