You're very close:

foreach( keys %hash2 ){

   if( exists $hash1{$_}  ){

      print "$_ = ",$hash2{$_}*$hash1{$_},"\n";
   }
}
[download]

btw.: please don't quote numbers (like '5') if you want them to be numbers and not strings: It's both confusing and (although only in microseconds) slows perl down.

my %hash = (
    dog => 11,
    budgie => 1,
   #...
)
[download]

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