Simple:
1/10 = 0.1
1/5 = 0.2
1/2 = 0.5
1/1 = 1.0
1/0.5 = 2.0
1/0.25 = 4
1/0.1 = 10
...
1/0 = ? (Infinity)
Fact: Our math is flawed.
You just took a limit from the right, so you got positive infinity. If you took the limit from the left, you would get negative infinity. If you took the limit from the left and right at the same time, what would you get? Besides, lim_x(f(x)) != f(x), necessarily. Our math is not flawed.
To add to what others have said about division by zero and complex numbers, you may want to know that 1 / 0 = complex infinity. Of course, this is outside of the real number plane, so you have to realize that 1 / 0 is well defined in some spaces, and 1 / 0 is undefined in other spaces.