问题 解答题

能用简便方法的用简便方法计算

6.48×909+6.48;6.8×9.9.

答案

(1)6.48×909+6.48

=6.48×(909+1)

=6.48×910

=5896.8

(2)6.8×9.9

=6.8×(10-0.1)

=6.8×10-6.8×0.1

=68-0.68

=67.32

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