So, to recap...

1. Find first non-zero digit
2. Look at the next digit
a. If the next digit is >= 5, round first digit up
b. If the next digit is < 5, do nothing to the first digit
3. Drop all digits after the (possibly adjusted) first digit
4. Keep leading zeros and decimal places intact

That is probably exactly what you already said, but I needed to put it in my own way.

If the above is true, then are these correct?

 4.008 *  2.09 ------> 4  *  2  =  8
38.002 *  0.49 ------> 40 *  .5 =  20
61.203 *  0.42 ------> 60 *  .4 =  24
  .98  *  7.61 ------> 1  *  8  =  8
  .098  * 0.15 ------> .1 *  .2 =  .02