9×9= 99×99= 999×999= 9999×9999= 99999×99999= 我能直接想出: 999999999×999999999=

问题描述:

9×9=
99×99=
999×999=
9999×9999=
99999×99999=
我能直接想出:
999999999×999999999=

解9×9=8199×99=9801999×999=9980019999×9999=9998000199999×99999=9999800001不用计算,直接写出999999999×999999999=999999998000000001故答案为:81,9801,998001,99980001,9999800001,9999999800000001...