my $c = 0; for ($x = 0; $x <= 1; $x += 0.05){ $c++; print "[$c] x= $x (".sprintf("%20.40f",$x).") \n"; } #### [1] x= 0 (0.0000000000000000000000000000000000000000) [2] x= 0.05 (0.0500000000000000027755575615628913510591) [3] x= 0.1 (0.1000000000000000055511151231257827021182) [4] x= 0.15 (0.1500000000000000222044604925031308084726) [5] x= 0.2 (0.2000000000000000111022302462515654042363) [6] x= 0.25 (0.2500000000000000000000000000000000000000) [7] x= 0.3 (0.2999999999999999888977697537484345957637) [8] x= 0.35 (0.3499999999999999777955395074968691915274) [9] x= 0.4 (0.3999999999999999666933092612453037872910) [10] x= 0.45 (0.4499999999999999555910790149937383830547) [11] x= 0.5 (0.4999999999999999444888487687421729788184) [12] x= 0.55 (0.5499999999999999333866185224906075745821) [13] x= 0.6 (0.5999999999999999777955395074968691915274) [14] x= 0.65 (0.6500000000000000222044604925031308084726) [15] x= 0.7 (0.7000000000000000666133814775093924254179) [16] x= 0.75 (0.7500000000000001110223024625156540423632) [17] x= 0.8 (0.8000000000000001554312234475219156593084) [18] x= 0.85 (0.8500000000000001998401444325281772762537) [19] x= 0.9 (0.9000000000000002442490654175344388931990) [20] x= 0.95 (0.9500000000000002886579864025407005101442)