Well, the original noder is wrong. Infinite can be treated as a number, but only in special cases. Here are a few from the wonderful world of Calculus (for the purpose of this node x->y means as the number that x represents gets closer and closer to the number that y represents, see limit):

as x->infinity, x/x = 1
one divided by infinity is an infinitely small number, and can in specialized places be treated as zero. See 1/infinity IE: as x->infinity, 1/x=0.
In

laymen's terms, as x gets closer and closer to infinity, 1/x gets closer and closer to zero. Whip out your

calculator and try it out!

as x->infinity, x/(x+1) = one

This is because as x approaches infinity, the one becomes negligible.
infinite divided by one is infinity.

Infinite can also be the answer in several problems:
as x->0, 1/x equals infinity/negative infinity, depending on whether x is approaching zero from the positive (more than zero, x becomes smaller and smaller, ie 9,8,4,1,0.5) or the negative (less than zero, x becomes greater and greater, ie -9,-8,-4,-1,-0.5) side.
as x->0, cosx/sinx = infinite/negative infinite

This is because as x->0, cosx gets closer and closer to one, and sinx gets closer and closer to 0, and 1/x as x->0 equals infinity/negative infinity, once again depending on whether x is approaching 0 from the positive or negative side.
Join me next week, as I discuss more fascinating mathematical concepts!