Final answer:
The CGRS keypad refers to a conceptual grid system used to pinpoint locations on Earth, not a physical keypad. It divides the Earth's surface into hierarchical grid cells of varying sizes, with the precise dimensions depending on the level of detail required, not the size of a physical keypad.
Step-by-step explanation:
The Common Geographic Reference System (CGRS) keypad is not a physical keypad but rather a grid-based reference system used to provide a standardized method of describing locations anywhere in the world. This system divides the Earth's surface into a hierarchy of grid cells of several sizes, but it doesn't specify the actual physical size of a keypad, since it's a conceptual tool, not a device.
The largest grid cells in the CGRS are typically 24 degrees of longitude by 24 degrees of latitude, and these are further subdivided down to smaller cells. For military or detailed navigation purposes, these grids are subdivided into smaller squares for precise reference, which could theoretically be mapped onto a virtual "keypad" for entering coordinates, but its size would depend on the device or the software interface being used.