9.9*2.8+28*0.01 巧算,递等式计算,蟹蟹!
问题描述:
9.9*2.8+28*0.01 巧算,递等式计算,蟹蟹!
答
9.9×2.8+28×0.01
=9.9×2.8+2.8×0.1
=(9.9+0.1)×2.8
=10×2.8
=28