in reply to map2 {} grep2 {} ...

%h_numbers = map { looks_like_number ($h{$_}) ? ($_, $h{$_}) : () } keys %h;

%h_numbers = map { @$_ } grep { looks_like_numebr ($_->[1]) } map { [ $_, $h{$_} ] } keys %h;


Enjoy, Have FUN! H.Merijn