Question 703864
>>...I am 4 digit number...<<
<pre>
So we have four blanks to fill in:
_ _ _ _
</pre>
>>...My tens digit is the smallest single digit possible...<<
<pre>
The ten's digit is 0 because it is the smallest single digit possible.

_ _ <u>0</u> _
</pre>
>>...My thousands digit is thrice as large as my digit in the ones place...<<
<pre>
The only digits that can be thrice another are 0,3,6,and 9, but 0
is out because the thousands digit can't be 0.  So that leaves 3,6,
and 9 for the thousands digit. 
</pre>
>>...My thousands digit is ... half that of my hundreds digit.
<pre>
The only one of those that can be half another digit is 3. So the
thousands digit is 3, 

<u>3</u> _ <u>0</u> _

And that 3 is thrice the units digit, making the units digit 1. 

<u>3</u> _ <u>0</u> <u>1</u>

And that 3 is also half the hundreds digit, making the hundreds digit 6.

<u>3</u> <u>6</u> <u>0</u> <u>1</u>

Edwin</pre>