Thanks for contacting us and reporting this issue. With your help we have been able to identify a small bug in RailClone. If a integer is used in the first input of an arithmetic operator, any float values attached to other inputs are rounded down to the nearest whole number. We will make sure this is fixed in the next update, meanwhile, as you've discovered, the solution is to swap the inputs so that the first number attached is a float value.
I'll also add the ability to see the result of calculations to our wish list.
Thanks again for the suggestions,