[request] [±] key, always as change of sign operator

[Han]

So when a user types 5+3 and places the cursor between the 5 and the +, should the negation key change the 5 to -5, or should it change the + symbol to - (subtraction)? I do not think that it would be easy to have a single key guess correctly 100% of the time as far as what the user intended is concerned.