800÷8×5 25+75÷5
305-78+22 (32+68)÷5
35×45﹣725 92×(18.6+11.4) 344+456÷8
①0.53×2.5+
②25×0.032×12.5
③ [()×]
④6.83+17.9﹣0.83+32.1