Sorting padded numbers?

[Luis Gomez]

Hi, quick one this time...

How can I make a map function sort these keys numerically? Is there an
easy/conventional way or do I need to pad the numbers?

1
10
11
12
13
14
15
16
17
18
19
2
20
21
22
23
24
25
26
27
28
29
3
30
31
32
33
34
35
36
37
38
39
...

Thanks,

Luis