题目
下面各题怎样简便就怎样算.
(1)
+ ÷4
(2)
2.5× ×0.4×
(3)
( ﹣ )÷
(4)
÷(3﹣ ﹣ )
答案: 57 + 27 ÷4 = 57 + 114 = 1114
2.5× 38 ×0.4× 49 =(2.5×0.4)×( 38 × 49 ) =1× 16 = 16
( 23 ﹣ 58 )÷ 124 =( 23 ﹣ 58 )×24 = 23 ×24﹣ 58 ×24 =16﹣15 =1
718 ÷(3﹣ 715 ﹣ 815 ) = 718 ÷[3﹣( 715 + 815 )] = 718 ÷[3﹣1] = 718 ÷2 = 736