①456-298
②679+204
③423-175+277-225
④873-48-152
⑤684-(432+184)
⑥348-158+52
①235×99
②357+245+755+643
③53×19+53×81
④2300÷25
⑤125×32×25
⑥816÷[(29-25)×12]
①273﹣73﹣27
②1.25×9.78×80
③()×24
④[1﹣()]÷