1) (637 + 1004) + 996 = 637 + (1004 + 996) = 637 + 2000 = 2637
2) 729 + (47 + 271) = 729 + 318 = 1047
3) 398989 + (201011 + 6482) = 398989 + 207493 = 606482
4) 15824 + (37301 + 24176) = 15824 + 61477 = 77301
1) (637 + 1004) + 996 = 637 + (1004 + 996) = 637 + 2000 = 2637
2) 729 + (47 + 271) = 729 + 318 = 1047
3) 398989 + (201011 + 6482) = 398989 + 207493 = 606482
4) 15824 + (37301 + 24176) = 15824 + 61477 = 77301