考點:分數(shù)的四則混合運算,分數(shù)的簡便計算
專題:運算順序及法則
分析:(1)按照從左到右順序計算解答,
(2)按照先算括號里面的,再算括號外面的順序計算解答,
(3)(5)(6)(7)(9)運用乘法分配律解答,
(4)(10)(12)按照先算小括號里面的,再算中括號里面的,最后算括號外面的順序計算解答,
(8)按照先同時計算第二級運算,再算第一級運算順序計算解答,
(11)按照先算除法,再運用加法結(jié)合律解答.
解答:
解:(1)
×
÷
=
÷
=1;
(2)
÷(
+
)
=
÷
=
;
(3)
×7+
×11
=
×(7+11)
=
×18
=10;
(4)[1-(
+
)]÷
=[1-
]÷
=
÷=1
;
(5)
×99+
=
×(99+1)
=
×100
=16;
(6)
×
+
÷1
=(
+
)×
=1×
=
;
(7)
÷7+
×
=
×(
+
)
=
×
=
;
(8)
×
+
÷
=
+2
=2
;
(9)
×24+
×24+
×24
=12+16+18
=46;
(10)7
÷[1
÷(4
-
)]
=7
÷[1
÷4
]
=7
÷
=24
;
(11)
+
÷
+
=
+(
+
)
=
+1
=1
;
(12)
÷[
-(
-
)]
=
÷[
-
]
=
÷
=
.
點評:(1)依據(jù)四則運算計算方法正確進行計算,(2)正確運用簡便方法解決問題,是本題考查知識點.