5分之16除以9分之5*16分之5
=16/5*5/16*9/5
=9/5
=1.8
4*0.8*0.25*12.5
=（4*0.25）*（0.8*12.5）
=1*10
=10
2.94*7分之3+4.06除以2又3分之1
=2.94*3/7+4.06*3/7
=（2.94+4.06）*3/7
=7*3/7
=3