合理、灵活地计算下面各题.0.25*16 3.14*45.4+54.6*3.14 6.15*9.4

问题描述:

合理、灵活地计算下面各题.0.25*16 3.14*45.4+54.6*3.14 6.15*9.4

(54.6+45.4)*3.14

0.25*16=0.25*4*4=1*4=4
3.14*45.4+54.6*3.14
=3.14*(45.4+54.6)
=3.14*100
=314
6.15*9.4
=(6+0.15)*(9+0.4)
=54+1.35+0.06+2.4
=54+1.41+2.4
=54+3.81
=57.81