(1)9×9=81 99×99=9801 999×999=998001 9999÷9999=1 99999÷99999=1 (2)(10-2)÷8=1 (100-12)÷8=11 (1000-112)÷8=111 (10000-1112)÷8=1111 (10000000-1111112)÷8=11111.