IF (a) we restrict values to 1..9 (i.e. not zero), and (b) do not allow duplication of letter assignments, there are seven ways for 2 WRONGs to make a RIGHT:

WRONG RIGHT

12734    25468

12867    25734

12928    25876

25938    51876

25734    51468

25867    51734

25938    51876

37846    75692

If zero is allowed (distinct assignments, from 0..9) there are 14 more solutions (total 21).  None with the first letter zero.

Edited on November 22, 2010, 2:23 pm

Posted by ed bottemiller on 2010-11-22 14:13:37