①4×(250-400÷16)
②5.5÷×
③3.6×+6.4×
④7-7×+
⑤+4.9++5.1
⑥(-0.8+)×12.5
①
②()÷
③
④-(÷-)
⑤19×(+)×37
⑥÷[(-)×6]
①101×32
②2.74+8.67+7.26+11.33
③18.8﹣5.8﹣﹣4.2﹣
④×+÷
⑤0.888×125×73+999×3
⑥4﹣[3.75×(1.2﹣)+]
①273﹣73﹣27
②1.25×9.78×80
③()×24
④[1﹣()]÷
②
④