3.75*0.5*2
=3.75*1
=3.75
4.8*0.25
=1.2*4*0.25
=1.2*1
=1.2
50.4*1.9-1.8
=95.76-1.8
=93.96
9.07-22.78÷3.4
=9.07-6.7
=2.37