1.6加23.4除以7.2
1.6+23.4÷9÷0.8
=1.6+2.6÷0.8
=1.6+13÷4
=1.6+3.25
=4.85
2.07除以0.23在除以0.45
=2.07÷0.9÷0.5÷0.23
=2.3÷0.23÷0.5
=10÷0.5
=20