You're right that ** works too, but you're wrong about it being faster (at least on my system). 
# srand(0) is used to make sure both
# subs are using the same input set.

sub m1 {
   unless ($i1) { srand(0); $i1=1; }
   $n = rand;
   $p = $n ** 2;
}

sub m2 {
   unless ($i2) { srand(0); $i2=1; }
   $n = rand;
   $p = $n * $n;
}


use Benchmark;
Benchmark::cmpthese(0, {
   '$n**2' => \&m1,
   '$n*$n' => \&m2,
});


__END__

           Rate $n**2 $n*$n
$n**2  722292/s    --  -29%
$n*$n 1013884/s   40%    --

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In reply to Re^3: Convert arithmetic expression from Excel to Perl syntax by ikegami
in thread Convert arithmetic expression from Excel to Perl syntax by ameyer

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