$ perl -e'printf qq[%s => %.68f => %.1f\n], (qq[0.${_}5]) x 3 for (0..
+9)'
0.05 => 0.050000000000000000000677626357803440271254658000543713569641
+11328125 => 0.1
0.15 => 0.150000000000000000005421010862427522170037264004349708557128
+90625000 => 0.2
0.25 => 0.250000000000000000000000000000000000000000000000000000000000
+00000000 => 0.2
0.35 => 0.349999999999999999994578989137572477829962735995650291442871
+09375000 => 0.3
0.45 => 0.449999999999999999989157978275144955659925471991300582885742
+18750000 => 0.4
0.55 => 0.550000000000000000010842021724855044340074528008699417114257
+81250000 => 0.6
0.65 => 0.649999999999999999978315956550289911319850943982601165771484
+37500000 => 0.6
0.75 => 0.750000000000000000000000000000000000000000000000000000000000
+00000000 => 0.8
0.85 => 0.850000000000000000021684043449710088680149056017398834228515
+62500000 => 0.9
0.95 => 0.949999999999999999989157978275144955659925471991300582885742
+18750000 => 0.9
[download]

$ perl -V
[download]