求教几道简便计算 9.8*25 2.01*31.4 3.8*41-3.8 3.78*4.5*0.2 198*0.51

问题描述:

求教几道简便计算 9.8*25 2.01*31.4 3.8*41-3.8 3.78*4.5*0.2 198*0.51

9.8*25
=9.8*100/(1/25*100)
=980/4
=245