I just test the version 2.7.10 and 3.5.2, on windows 7 SP1 x86, windows 7 SP1 x64 and linux debian amd64.

I hope can get the answer from you quickly, thanks.

18.35 - 9.35

9.000000000000002

18.35 - (12 - 2.65)

9.000000000000002