The simplest answer is: you have a 50% chance of the number being > .5 and a 50% chance of getting a number > num1 +num2 >=1 so the answer is 2 draws. people are trying to show these grand equations to figure it out, but it's really a simple solution; Most of the time it take 2 draws.

Use your mind, which is enormously greater at making common sense solutions than a computer, and figure it out with common sense, then test it with an algorithm.