五年级下册分数加减法和简便计算题,急如:分数:1/2+3/4-3/10=10/20+15/20-6/20=19/20如计算:12.5X7.4X0.8=12.5X0.8X7.4=74

Question

五年级下册分数加减法和简便计算题,急
如:分数:1/2+3/4-3/10
=10/20+15/20-6/20
=19/20
如计算:12.5X7.4X0.8
=12.5X0.8X7.4
=74

Answer 1

2/3+1/12-2/6 3/4-2/4+4/16 懒懒的我 先答两道吧 嘿嘿
=8/12+1/12-4/12 =12/16-8/16+4/16
=5/12 =8/16
=1/2