So, I said I was going to post weekly, then school happened. I need to set a reminder or something. At any rate, I found this interactive game for Coordinate Grids. This activity allows the user to plot points on the coordinate plane and to read the coordinates of a point plotted by the computer.
The Cartesian coordinate system was formalized by Rene Descartes in the 17th century to help visualize functions via plotting function values as ordered pairs. The story of how the system was developed is that Descartes was sick. As Rene' Descarte lay in bed sick, he saw a fly buzzing around on the ceiling. His ceiling was made of square tiles. As he watched, he realized that he could describe the position of the fly by the ceiling tile he was on. After this experience, he developed the Cartesian coordinate system in the 17th century to help visualize functions via plotting function values as ordered pairs. In this system a grid of evenly spaced horizontal and vertical lines is drawn, a center or "origin" is chosen, and horizontal and vertical scales are chosen.