18×37﹣49
(672﹣336)÷6
108×3÷4
(504﹣465)×23
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)÷ ]
①54×98
②(+﹣)×24
③4.86×[1÷(2.1﹣2.09)]
④8﹣
①6.4×2.5×1.25
②8.5×98%
③÷4+×
④×