简便计算4.2x0.99

2025-06-28 04:20:07
推荐回答(1个)
回答1:

4.2*0.99
=4.2*(1-0.01)
=4.2*1-4.2*0.01
=4.2-0.042
=4.158
拆分,运用乘法分配律,凑整,简便运算