Tips breakthecode

Try to use extreme-value strategies from puzzles like CrossSums (Kakuro). It may be possible to eliminate the most extreme (highest/lowest) possibilities for some of the numbers--especially once you know something about the rest of them. One example: the highest digit out of 5 cannot be 0 or 1, since there are only 4 digits in the range 0-1; similarly the lowest digit cannot be 8 or 9.