<PRE><B>Question 1148540</B>
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1xx1: the two middle digits must sum to 0; clearly only 1 number that satisfies the condition: 1001&lt;br&gt;
1xx2: the two middle numbers must sum to 1; they can only be 01 or 10.  So 2 numbers: 1012 and 1102&lt;br&gt;
1xx3: the two middle numbers must sum to 2; they can only be 02 , 11, or 20.  So 3 numbers: 1023, 1113, and 1203&lt;br&gt;
...&lt;br&gt;
the pattern should be clear&lt;br&gt;
...&lt;br&gt;
1xx9: 9 numbers&lt;br&gt;
Then with leading digit 2 and less than 2013 there is only 1 number that satisfies the condition: 2002&lt;br&gt;
ANSWER: (1+2+3+...+9) + 1 = 45+1 = 46&lt;br&gt;
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