use strict;
use warnings;

use Benchmark;
my $x = 5;

timethese(-5, {
 EXPANDED=>sub { eval '$x * 24 * 60 * 60' },
 NOT_EXP =>sub { eval '$x * 86400' },
});

Benchmark: running EXPANDED, NOT_EXP, each for at least 5 CPU seconds...
  EXPANDED:  6 wallclock secs ( 5.31 usr +  0.00 sys =  5.31 CPU) @ 5677.40/s (n
=30147)
   NOT_EXP:  6 wallclock secs ( 5.26 usr +  0.00 sys =  5.26 CPU) @ 6749.24/s (n
=35501)