Out of curiosity... C:\>ruby --version ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] C:\>irb irb(main):001:0> 999999999999999 - 99999999999999

Out of curiosity... C:\>ruby --version ruby 1.8.6 (2008-08-11 patchlevel 287) [i386-mswin32] C:\>irb irb(main):001:0> 999999999999999 - 999999999999997 => 2 irb(main):002:0> 9999999999999999 - 9999999999999997 => 2 irb(main):003:0> 999999999999999.0 - 999999999999997.0 => 2.0 irb(main):004:0> 9999999999999999.1 - 9999999999999997.1 => 2.0