题目内容
能简便计算的用简便方法计算.
| ( | ||
解:(1)
÷
×
,
=
,
=1
;
(2)
×
+0.25×
-
,
=0.25×(
-1),
=0.25×0,
=0;
(3)(
+
)÷
,
=
+
,
=1
+1,
=2
;
(4)
×
+
÷
,
=
(
),
=
,
=
;
(5)
÷[(
+
)×
],
=
÷[
×
],
=
,
=3;
(6)
+
+
+
+…
,
=1-
+
-
+
+
…+
,
=1-
,
=
.
分析:(1)(5)依据四则运算计算顺序,先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答,
(2)(3)(4)运用乘法分配律间的,
(6)化
=1-
,
=
-
,
=
,
=
…
=
即可解答.
点评:本题考查知识点:(1)依据四则运算顺序正确进行计算,(2)正确运用简便算法解决问题.
=
=1
(2)
=0.25×(
=0.25×0,
=0;
(3)(
=
=1
=2
(4)
=
=
=
(5)
=
=
=3;
(6)
=1-
=1-
=
分析:(1)(5)依据四则运算计算顺序,先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答,
(2)(3)(4)运用乘法分配律间的,
(6)化
点评:本题考查知识点:(1)依据四则运算顺序正确进行计算,(2)正确运用简便算法解决问题.
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