0.35*1.25*2.08=
0.5*7*0.05*5*5*0.52*4=
0.5*7*0.05*5*20*0.52=
10*7*0.05*5*0.52=
7*0.5*5*0.52= 0.5*5*2.6=6.5
7*0.5*5*0.52=
0.5*5*2.6=6.5
0.35×1.25×2.08=0.35×1.25×0.13×2×8=（0.35×2）×（1.25×8）×0.13=0.7×10×0.13=7×0.13=0.91
