Does it depend on the number of starter numbers you're given in the puzzle? I've been doing the ones in the D Telegraph and have progressedfrom being unable to do the childrens one [Saturdays] to actually finishing a diabolical [their description] one last week. [Took ages and lots of paper]
Bloody things addictive!
Anyway back to Kag's question, I think there's only one possible solution if you're given a few numbers to start with but I too have wondered how few numbers you'd need to get multiple solutions. OMG! I've turned into a nerd! I'm not really, can't beleive I'm spending my precious time on maths puzzles!
Jimbo
ha - yes, I'm addicted too despite initially dismissing them as nerdy! - I realise that there is only one possible solution when you are given starter numbers, I just wondered how many different ways the 81 numbers could be put into the grid in the first place. Thank you sddsddean, given the different amounts and combinations of starter numbers I guess we won't run out for a while!