(1993×1994-1)÷(1993+1992×1994)
525.7-200.9+ 74.3
①57×
②21.36-(7.36-6.7)
③÷[2-(+)]
④3.75×99+3.75
⑤×9+7÷
⑥25%××
①3.86+6.4+2.14+7.6
②5.2÷0.32﹣0.12
③()×15
④
⑤
⑥