question_answer 9)

Find the sum by suitable rearrangement. (a) 837 + 208 + 363           (b) 1962 + 453 + 1538 + 647 TIPS Sum of three or more than three whole numbers remains same on changing the grouping of the numbers and we group the numbers for convenience of adding. This property is known as associativity of addition for whole numbers.

Answer:

                (a) We have, 837 + 208 + 363 = (837 + 363) + 208                [by associative property] = 1200 + 208 = 1408 (b) We have, 1962 + 453 + 1538 + 647 = (1962 + 1538) + (453 + 647) = 3500 + 1100 = 4600 Note We rearrange the number in such a way that new number obtained after rearrangement has zero.