Eric is on a treasure hunt, but he must first learn to use a grid plan! You can learn to read a grid map and help Eric to locate the treasure. It's not magic ... it's mathematical! The Pedagogical Side: This segment is about grids, coordinates and cartographic representation, with an emphasis on the mathematical skills of reading and representing location data using geometry. Grids and grid planes illustrate the concepts of parallel / transverse lines (identified lettered and numbered axes or lines), ordered pairs, and intersection points.