3999ⅹ498的简便运算

2024-12-28 23:19:10
推荐回答(1个)
回答1:

3999ⅹ498
=(4000-1)x498
=4000x498-498
=4000x(500-2)-498
=4000x500-4000x20-498
=2000000-(80000+498)
=2000000-80498
=1991502