print int($x*100 + 0.5)/100 ;

##</code><code>##

sub show {
 my ($y, $p) = @_ ;
 my $x = $y + 0 ;
 my $t = $p + 4 ;

 print  "Original value = $y, format = %${t}.${p}f\n" ;
 printf "                   \$x = %${t}.${p}f\n", $x ;
 printf "               \$x*100 = %24.20f (%%24.20f)\n", $x * 100 ;
 printf "      int(\$x*100)/100 = %${t}.${p}f\n", int($x*100)/100 ;
 printf "int(\$x*100 + 0.5)/100 = %${t}.${p}f\n", int($x*100 + 0.5)/100 ;
} ;

show("1.15", 20) ;