No no no! You've all got something wrong. Let me explain...
infinity + infinity = infinity
infinity - infinity = undefined
infinity * infinity = infinity
infinity / infinity = undefined
infinity / 0 = infinity
infinity / a very small postivive number, which approches 0 = infinity
infinity/ a very small negative number, which approches 0 = - infinity
a number / infinity = 0 (approches 0 actually, but....)
a number / 0 = undefined
- infinity * infinity = - infinity
- infinity * - infinity = infinity
infinity / - infinity = undefined
Very simple College Maths, isn't it?
(Surely isn't...

)