What if you made a series of unit fractions with the odd numbers as their denominator, added the first two together, subtracted the next one, added the next one and so on. And finally multiplied that number by 4? What number would you get?

# Category: Math and Design

# String Diagrams

The usual way to make string diagrams using rubber bands or yarn on a board with nails does not allow much exploration. Mary Boole meant them as exercises in visualization. Building these diagrams using spreadsheets not only shows their versatility and capability for artistic expression, it helps students get used to using ordered pairs and axes of different sorts and thus builds their graphic sense. There are so many possibilities that you might think of having contests for the most interesting and thought provoking diagrams.

# Drawing Triangles

Though spreadsheets lets you put geometric shapes on the screen, those shapes are not connected with the cells and cannot be changed by using different values. We wanted to make geometric shapes that we could control and change by changing parameters. This is our first try. You can learn to use linear functions to create and change a triangle. It is pretty cool. This Lab involves many different aspects of mathematics from geometric shapes to graphing, from slope to linear functions, from perpendicular lines to the definition of function.

# Sudoku Challenge

Have you ever played Sudoku? It is fun and challenging. You have to find the numbers from 1 to 9 in each cell so that that all of the numbers appear only once in every row, column, and grid square. Ryan added a sweet wrinkle to the traditional Sudoku game, he gives you the sums so that you not only get to practice addition, you can get some hints about the numbers you should input. Can you use our template to create your own Sudoku challenge?

# Projectile Motion

Let’s do a little target practice with this spreadsheet projectile simulator, which will map out the flight path of an arrow shooting toward a target.