perl -E'
$h={foo=>{bar=>10000000000},baz=>{bar=>70000000},qux=>{bar=>20000000000}};
say "$_: $h->{$_}->{bar}" for sort { eval { say $h->{$b}->{bar}. " - ".$h->{$a}->{bar}." = ".($h->{$b}->{bar} - $h->{$a}->{bar}); $h->{$b}->{bar} - $h->{$a}->{bar} } } keys %$h;
'
10000000000 - 70000000 = 9930000000
20000000000 - 10000000000 = 10000000000
qux: 20000000000
foo: 10000000000
baz: 70000000

##</code><code>##

perl -E'
$h={foo=>{bar=>10000000000000},baz=>{bar=>70000000},qux=>{bar=>20000000000000}};
say "$_: $h->{$_}->{bar}" for sort { eval { say $h->{$b}->{bar}. " - ".$h->{$a}->{bar}." = ".($h->{$b}->{bar} - $h->{$a}->{bar}); $h->{$b}->{bar} - $h->{$a}->{bar} } } keys %$h;
'
20000000000000 - 70000000 = 19999930000000
10000000000000 - 70000000 = 9999930000000
foo: 10000000000000
baz: 70000000
qux: 20000000000000