When I was studying mathematics in school, we used to have "x"(cross) as multiplication operator. Consequently, "⋅"(dot) became the multiplication operator, then came "*"(asterick).
Similarly for division I had seen: ÷, / and — (its not minus-read long dash) operators
But I really have no idea of why so much overriding for the same operators. Is there any specific reason of using specific operator for specific operations-for example, fractions generally use — division operator (I have seen ÷ rarely to be used to depict fraction)
Also, I have not seen addition and subtraction operators to be changing so drastically with contexts?