Candidates

[stolfa]

On larger Kenken puzzles I always start by using candidates. I go through the whole grid one at a time using the "+" to enter the possible candidates. Is there a global command that will fill in the candidates across the whole puzzle? There should be. I wast a minute or two doing this on every puzzle. It is more a test of dexterity than logic power!

Dave

[doromo]

I used to do that. I filled the entire grid with all the numbers as you described. I have found that it is not too helpful because it gives you too many candidates to work with. For example, how does it help when you need 6 numbers to add to 22? or 5 numbers that multiply to 144? There are just too many possibilities!

I start by marking all locked pairs (or triples) that are the only possibilties, like 2x7 = 14 or 1x5x7 = 35 or 8+9 = 17, or 1-9 = 8, etc. I then see if by marking out the "solved" candidates that I can identify the rest of that row or column. For example, if 8 is taken then 4/ must be 1 and a 4; if 2 is used already then 30x must be 1x5x6, etc. I then reiterate to see if I can solve the rest of that row or column. By this time, I usually have 1 or 2 squares solved and I keep expanding to other parts of the puzzle.

I find that I am able to solve most puzzles rather efficiently this way and I don't need the + button until the very last part of the solution. In general, I do not like to have more than 4 candidates in any single square since it does not give me very much information.

[diacoyani]

My approach is the same as Doromo's. In KenKen the math operations should be used first to obtain the least number of candidates and in many cases some solutions along the way. This is the fun part of KenKen.