0.56÷0.8= = = =
5×( )= 30×= 0.53= 3﹣=
①57.6﹣18.15+32.4﹣11.85
②78×25+1764÷49
③2.5×32×12.5
④3.6×[(37.5+18.5)÷2.8]
⑤÷[(﹣)×]
⑥199×99+178+21