As for the rounding error question, I don't think we'll have too much trouble with it. Just check the result to be within an error margin as I did in my version of the test program. It should work for all situations: with just 3 operations, you will surelly not have an error THAT big... Besides, with only 4 1-digit numbers and 3 operations, you would not arrive to a "near-perfect" score unless it's a correct answer...

As for the nested parentheses, in fact I had not noticed that I'd raise such an issue! [Smile] As I said in another post, I was simply laying down the options to have a clearer view of the problem and potential solutions... Being as it is, that this is a "game" about program size and not efficiency, I may as well end up using all parentheses if that simplifies my code in any way... [Smile]
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Later,   [b]Mad[/b]ruga