<PRE><B>Question 974656</B>
&lt;pre&gt;
Multiplication of a 3-digit number by a single digit can be 
performed like these two examples below:

  943                    458
  &lt;u&gt;  7&lt;/u&gt;                    &lt;u&gt;  9&lt;/u&gt;
   21 &lt;--7x3              72  &lt;--9x8
  28  &lt;--7x4             45   &lt;--9x5
 &lt;u&gt;63  &lt;/u&gt; &lt;--7x9            &lt;u&gt;36  &lt;/u&gt;  &lt;--9x4
 6601                   4122

So let QxQ=AB and QxP=CD

  PPQ
  &lt;u&gt;  Q&lt;/u&gt; 
   AB &lt;--QxQ
  CD  &lt;--QxP
 &lt;u&gt;CD  &lt;/u&gt; &lt;--QxP
 RQ5Q

B must = Q, since we bring it down to the bottom line

  PPQ
  &lt;u&gt;  Q&lt;/u&gt; 
   AQ &lt;--QxQ
  CD  &lt;--QxP
 &lt;u&gt;CD  &lt;/u&gt; &lt;--QxP
 RQ5Q 

We need Q so that QxQ ends in Q
1x1=1, 2x2=4, 3x3=9, 4x4=16, 5x5=25, 6x6=36, 7x7=49, 8x8=64, 9x9=81

Since QxQ must end in Q, Q is 6, since Q obviously can&#39;t be 1.
Therefore AQ must be 36.

  PP6
  &lt;u&gt;  6&lt;/u&gt; 
   36 &lt;--6x6
  CD  &lt;--6xP
 &lt;u&gt;CD  &lt;/u&gt; &lt;--6xP
 R656

In order to get the 5 on the bottom line, D must be 2.

  PP6
  &lt;u&gt;  6&lt;/u&gt; 
   36 &lt;--6x6
  C2  &lt;--6xP
 &lt;u&gt;C2  &lt;/u&gt; &lt;--6xP
 R656

In order to get the left-most 6 on the bottom line, C must be 4,

  PP6
  &lt;u&gt;  6&lt;/u&gt; 
   36 &lt;--6x6
  42  &lt;--6xP
 &lt;u&gt;42  &lt;/u&gt; &lt;--6xP
 R656
 
and then P must be 7, since 6x7=42

  776
  &lt;u&gt;  6&lt;/u&gt; 
   36 &lt;--6x6
  42  &lt;--6x7
 &lt;u&gt;42  &lt;/u&gt; &lt;--6x7
 R656

Finally R can only be 4

  776
  &lt;u&gt;  6&lt;/u&gt; 
   36 &lt;--6x6
  42  &lt;--6x7
 &lt;u&gt;42  &lt;/u&gt; &lt;--6x7
 4656

Edwin&lt;/pre&gt;</PRE>