0.25+5.2+9.75+84.8
=0.25+9.75+84.8+5.2
=10+90
=100
（2）8/1.6+8.4*2.7
=80/16+22.68
=5+22.68
=27.68
（3）16.2/1.5*0.24
=32.2*0.24/3
=32.2*0.08
=2.576