题目内容
计算.(能简算的要简算)
[1-(
+
)]÷
(
-
)×45
÷
-
×
÷7+
×
.
[1-(
| 1 |
| 4 |
| 3 |
| 8 |
| 1 |
| 4 |
(
| 1 |
| 3 |
| 1 |
| 5 |
| 19 |
| 13 |
| 7 |
| 5 |
| 6 |
| 13 |
| 5 |
| 7 |
| 8 |
| 13 |
| 1 |
| 7 |
| 6 |
| 13 |
分析:(1)按照先算小括号里面的,再算中括号里面的,最后算括号外面的顺序解答,
(2)(3)(4)运用乘法分配律解答.
(2)(3)(4)运用乘法分配律解答.
解答:解:(1)[1-(
+
)]÷
=[1-
]÷
=
÷
=1
;
(2)(
-
)×45
=
×45-
×45
=15-9
=6;
(3)
÷
-
×
=(
-
)×
=1×
=
;
(4)
÷7+
×
=(
+
)×
=
×
=
.
| 1 |
| 4 |
| 3 |
| 8 |
| 1 |
| 4 |
=[1-
| 5 |
| 8 |
| 1 |
| 4 |
=
| 3 |
| 8 |
| 1 |
| 4 |
=1
| 1 |
| 2 |
(2)(
| 1 |
| 3 |
| 1 |
| 5 |
=
| 1 |
| 3 |
| 1 |
| 5 |
=15-9
=6;
(3)
| 19 |
| 13 |
| 7 |
| 5 |
| 6 |
| 13 |
| 5 |
| 7 |
=(
| 19 |
| 13 |
| 6 |
| 13 |
| 5 |
| 7 |
=1×
| 5 |
| 7 |
=
| 5 |
| 7 |
(4)
| 8 |
| 13 |
| 1 |
| 7 |
| 6 |
| 13 |
=(
| 8 |
| 13 |
| 6 |
| 13 |
| 1 |
| 7 |
=
| 14 |
| 13 |
| 1 |
| 7 |
=
| 2 |
| 13 |
点评:本题主要考查学生依据四则运算计算方法,以及正确运用简便方法解决问题的能力.
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