①16.2÷（48.6+5.4）×0.5 
=16.2÷54×0.5
=0.3×0.5
=0.15
 
②33.5-（15.3-3.5）
=33.5+3.5-15.3
=37-15.3
=21.7
③0.87×3.16+4.64
=2.7492+4.64
=7.3892