题目
脱式计算。
(1)
×( + - )
(2)
240×(1-25%)÷
(3)
× - ÷4
答案: 726 ×( 56 + 17 - 23 ) =726×(3542+642-2842) =726×(4142-2842) =726×1342 =112
240×(1-25%)÷ 25 =240×34×52 =180×52 =450
1255 × 78 - 1255 ÷4 =1255 × 78 - 1255×14 =1255×(78-14) =1255×(78-28) =1255×58 =322