text: 3/5 = 0.6\n9/8 = 1.125\n\nso 0.6 - 1.125 = -0.525\n\nor depending on whch way you do it\n\n1.125 - 0.6 = 0.525\n\nOR:\n\n3/5 - 9/8 = 24/40 - 45/40\n          = - 21/40\n          = -0.525\n\nAnd it works the same the other way round.\n\nHmm, did I do that correctly?  ;P