The  <=> numeric comparison automatically numerifys to a decimal number before the comparison:

>perl -wMstrict -le
"my @l = qw(10 010 0010  8 08 008  9 09 009  1 01 001);
 @l = sort { $a <=> $b } @l;
 print qq{@l};
"
1 01 001 8 08 008 9 09 009 10 010 0010
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