①7+8-9=
②18-5-8 =
③12-9+8=
④27+40 +2=
⑤83-(36-30)=
⑥54+(13+7)=
44-1= 36+2= 44-4= 79-4= 66-4=
52+7= 35+4= 49-6= 96-2= 25+4=
47-3= 53+5=
①﹣(+)
②8.89﹣1.84﹣3.16
③÷9+×
④12.5×0.32×2.5
①-+-
②×+÷
③(6﹣1.3×4)÷0.1
④0.4×0.25×8×125
⑤3.4÷[(1.25+0.45)×23]