Since noone has mentioned it so far I'd just like to point out that for Perl versions >= 5.9.3 you can use the smart match operator ~~ for this. So for example, the following would work:

use feature ":5.10"; 
my $x=10; 
my $y="10.00"; 

say "matches" if ($x ~~ $y);
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(tested with 5.9.5). See perlsyn for details on how smart match works.