Are you looking for a FLOAT (non-whole number) or a Integer?
The random number generator is under Math->Misc->Random Number
To generate a 1 or 0 then just configure it to do so.
If you want a floating point number set a floor of 0 and a ceiling of 100 and then divide by 100. You will need to cast it though so make sure you do that.
declare a local variable: float myRandomPercent = 0;
call the random generator
then make an assignment myRandomPercent = (float)(randomInt / 100);