A magic square is an arrangement of numbers from 1 to n2 in an n x n matrix. In a magic square each number occurs exactly once such that the sum of the entries of any row, column, or main diagonal is the same. You can make several magic squares and investigate the different properties of the square. Can you make an algorithm for constructing a Magic Square? Can you show that the sum of the entries of any row, column, or main diagonal must be n(n2+1)/2? Are there any other hidden properties of a…
Read more

Almost all of the games we play are based on math in some way or another. Card games, board games, and computer games are designed using statistics, probabilities, and algorithms. Begin by reading about games and game theory. Then you can choose your favorite game and investigate the mathematical principles behind how it works. Can combinatorial game theory help you to win two-player games of perfect knowledge such as go, chess, or checkers? (Weisstein, 2006; Watkins, 2004) In a multi-player…
Read more

Imagine a symmetrical grid of nine points superimposed over the ball. Kicking the ball squarely on the center point imparts no spin, but kicking on any of the other points will impart spin on the ball. How will the resulting spin affect the trajectory of the ball for each of the 8 outer grid points? Kicking the ball with a sliding motion of the foot is another way to impart spin. Once you've made your predictions, you can set up to test them with a soccer ball, video camera and a tape…
Read more

You may know Lewis Carroll as the author of Alice in Wonderland, but did you know that in real life he was a mathematician who studied symbolic logic and logical reasoning? How can math help you solve Lewis Carroll's Logic Game? (Bogomolny, 2006) How are algorithms for solving the game Sudoku similar to solving a logic problem? (Hayes, 2006) For the super-advanced mathematical genius, try to evaluate currently available, logic-based computational tools, or design a better one!…
Read more

What do knots, maps, mazes, driving directions, and doughnuts have in common? The answer is topology, a branch of mathematics that studies the spatial properties and connections of an object. Topology has sometimes been called rubber-sheet geometry because it does not distinguish between a circle and a square (a circle made out of a rubber band can be stretched into a square) but does distinguish between a circle and a figure eight (you cannot stretch a figure eight into a circle without…
Read more

Start with 7 drinking straws and 14 paper clips. Use the paper clips to fasten the straws together. Here's how: 1) Clip two paper clips together, narrow end to narrow end. 2) Push the wide ends of each clip into the end of a straw. That's it! Connect four straws to make a square, and three straws to make a triangle. Now test which shape is stronger. Hold the shapes vertically, with an edge or a vertex resting on the tabletop. Have a helper push on the opposite side or vertex. Which shape…
Read more

You can measure the diameter of the Sun (and Moon) with a pinhole and a ruler! All you need to know is some simple geometry and the average distance between the Earth and Sun (or Moon). An easy way to make a pinhole is to cut a square hole (2-3 cm across) in the center of a piece of cardboard. Carefully tape a piece of aluminum foil flat over the hole. Use a sharp pin or needle to poke a tiny hole in the center of the foil. Use the pinhole to project an image of the Sun onto a wall or piece…
Read more

If you like to play Tetris, then you might like this project. You will learn something interesting about the mathematics of complex shapes as you try to prove Pick's Theorem.
The strange shape below is an example of a lattice polygon, which is a polygon whose vertices lie on points in the plane that have integer coordinates.
As you can see, it is a complex shape, but there is an easy way to calculate its area, by simply counting lattice points!
If you count the number of lattice points on…
Read more

When the punter is trying to hit the "coffin corner" (within the opposing team's 10-yard line), out of bounds, what is the best angle to kick the ball for correct distance and maximum "hang time?" (For more information on the physics involved, see: Gay, 2004, Chapters 4 and 5.)
Read more

Here's an interesting project idea with a variation that combines computer science, physics and music. You'll need a piano in a quiet room, a microphone and a computer with digital sound recording and analysis software. The project shows you how you can make a piano string start vibrating without hitting its key. You can record the sounds on the computer, and use sound analysis software to measure the frequencies of the induced vibrations. For more details see: . Be sure to check out the…
Read more