①#(-)÷
②# 8.8-6.75+9.2-0.25
③÷(-)×
④÷[(-)×)]
15÷20= 78÷26= 26÷4=
30÷7= 91÷13= 18÷21=
= = =
= =
和
14和8
15和45
27和18
11和7