[noswi]

From programming perspective, there's nothing sufficiently preposterous in the idea of dividing by zero that would require bringing the whole world to a low-level halt just for attempting that by default. You tried to calculate the average value of what turned out to be an empty list? Go suffer the most severe exception, like the ones reserved for those reading from nonexistant memory.

[Asraelite]

Another common case is adjusting some value according to a spatial vector's magnitude, like normalizing a vector or scaling gravitational attraction according to the distance between two points.

In the majority of these cases the most reasonable answer is 0.