fix( 1.9*10) = 18 ?????

hi , all

why fix( 1.9*10) = 18 ?????

how to Fix( ) get the right value and a fast speed ?

methode 1: debug.print fix( cdec(1.9) *10) ..... 100% success but cdec very slow
methode 2: debug.print fix( cvar(1.9) *10) ..... fast than cdec() but not is 100% success