$ perl -e 'printf " %.1f => %.0f\n", $_, $_ for qw  / .5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5/;'
 0.5 => 0
 1.5 => 2
 2.5 => 2
 3.5 => 4
 4.5 => 4
 5.5 => 6
 6.5 => 6
 7.5 => 8
 8.5 => 8
 9.5 => 10

##</code><code>##

$ perl -e 'printf " %.0f \n", 3461.5;'
 3462

$  perl -e 'printf " %.0f \n", 3462.5;'
 3462


##</code><code>##

$ perl -e 'printf " %.0f \n", 3010*1.15,'
 3461

##</code><code>##

$ perl -e 'printf "%.15f \n",  3010*1.15,'
3461.499999999999545

##</code><code>##

$ perl -e 'printf "%.19f \n",  1.15;'
1.1499999999999999112

##</code><code>##

$ perl -e 'printf " %.0f \n", 301*11.5;'
 3462

##</code><code>##

$ perl -E 'say 301*11.5 - 3010*1.15;'
4.54747350886464e-13