I think the best way is to break 442 into its prime factors: 442 = 2×13×17 The prime factors are 2,13, and 17 So there are three pairs you can make by grouping two of them and taking the product of the two grouped times the third: 2×(13×17) = 2×221, and the sum of 2+221 is 223, not 43 (2×17)×13 = 34×13, and the sum of 34+13 is 47, not 43. (2×13)×17 = 26×17, and the sum of 26+17 is 43, so the answer is 26 and 17. Edwin