1简便计算.0.99*39 8.52*9.9+0.852 1.25*2.7/*0.8

0.99*39=1*39-0.39=38.61
8.52*9.9+0.852=0.852*100=85.2
1.25*2.7*0.8=1.25*0.8*2.7=2.7
⑴5.6与0.7的和,乘1与0.4的差,积是多少?
(5.6+0.7)*(1-0.4)=3.78
⑵比2.4多1.2的数,除以1.6的一半,商是多少?
(2.4+1.2)÷(1.6/2)=4.5