Working with geospatial data is notoriously difficult because latitude and longitude are floating point numbers and should be very precise. In addition, it would seem that latitude and longitude can be represented as a grid, but in fact, they can't, simply because Earth is not flat, and mathematics is a complex science.
For example, to determine the distance of a great circle between two points on a sphere, based on their latitude and longitude, the haversine formula is used, which looks like this: