$ perl -e' printf "%.20f\n", 1.6;'
1.60000000000000008882

##</code><code>##

$ perl -e'
   for ($i=1.1;$i<=1.6;$i+=.1) { printf "%.20f\n", $i; }
   printf "\n%.20f\n", $i;
'
1.10000000000000008882
1.20000000000000017764
1.30000000000000026645
1.40000000000000035527
1.50000000000000044409

1.60000000000000053291

##</code><code>##

$ perl -le'for my $i (1..6) { print 1+$i/10 }'
1.1
1.2
1.3
1.4
1.5
1.6