A mapping program includes an overlay grid of intersecting lines represented by two series of numbers. An origin is defined and an area of interest is defined. The origin corresponds to a location on a map. One series of numbers relates to longitude; while the other series of numbers relates to latitude. Each series of numbers are represented by two or more digits. Each digit represents up to 35 different numerals or letters. When two digits are used to represent a location, the combined number of lines for each series of number may comprise up to 1225 lines. Thus, the total number of lines represented by each series of number corresponds to a power of the base number of possibilities up to 35; the power being represented by the number of digits used in each series of numbers. These numbers are overlaid onto a map having points corresponding to actual longitudinal and latitudinal locations. A device for converting between the latitude and longitude is provided. A storage medium is also provided for storing a series of steps to perform the operations.