①200-160÷5
②90÷5×60
③(180+423)÷3
④30×34+260
①250-250÷25×2
②18÷ ×
③5.2÷0.4÷2.5
④(34- )÷17
⑤4.3×1.75-1.75+ ×6.7
⑥ ×[(72.8-69.6)÷ ]
①
②36×()
③
④
⑤3.24×0.76+3.24×0.24
⑥
①(3618÷18-145)×20
②6÷ - ÷6
③(21+ )× +
④ ×[ ÷( - )]
⑤3.5×98+35×0.2