Compare the numbers digit by digit, starting from the left.<br><br>
The numbers: 52 318, 52 813, 51 328, 52 138<br><br>
&bull; Ten-thousands digit: all are 5, so all in the fifty-thousands. Move to the thousands digit.<br>
&bull; Thousands digit: 51 328 has 1 (smallest so far).<br>
&bull; The other three have thousands digit 2: 52 318, 52 813, 52 138.<br>
&bull; Compare hundreds: 52 138 has 1 (smallest among the three), then 52 318 has 3, then 52 813 has 8.<br>
&bull; Order: 51 328, 52 138, 52 318, 52 813.<br>
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Final Answer: 51328, 52138, 52318, 52813