Dear All, I have encountered a strange calculation in perl. I have a value which i get in the function ($x ) and his value is 1 . Now i show from the debugger a snippet. DB<3> x $x 0 1 DB<4> x 1-$x '-2.22044604925031e-16' Has anyone an explanation of it how 1-1= '-2.22044604925031e-16' ? Thanks in advance, Michael