题目内容
脱式计算,能简算的要简算.
15÷
|
|
| ||||||||||||||||||
| 5×
|
|
考点:分数的四则混合运算
专题:运算顺序及法则
分析:(1)(3)(5)运用乘法分配律解答,
(2)按照先算括号里面的,在从左到右顺序计算解答,
(4)按照先同时计算乘法,再算加法顺序计算解答,
(6)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计算解答.
(2)按照先算括号里面的,在从左到右顺序计算解答,
(4)按照先同时计算乘法,再算加法顺序计算解答,
(6)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计算解答.
解答:
解:(1)15÷
+15÷
=15×(
+4)
=15×
=80;
(2)
÷(
+
)×2
=
÷
×2
=
×2
=1
;
(3)
÷19+
×
=(
+
)×
=1×
=
;
(4)
×
+
×
=
+
=
;
(5)5×
+5.5×80%+0.8
=(5+5.5+1)×0.8
=11.5×0.8
=9.2;
(6)
×[
-(
-
)]
=
×[
-
]
=
×
=
.
| 3 |
| 4 |
| 1 |
| 4 |
=15×(
| 4 |
| 3 |
=15×
| 16 |
| 3 |
=80;
(2)
| 4 |
| 5 |
| 3 |
| 5 |
| 1 |
| 2 |
=
| 4 |
| 5 |
| 11 |
| 10 |
=
| 8 |
| 11 |
=1
| 5 |
| 11 |
(3)
| 8 |
| 17 |
| 1 |
| 19 |
| 9 |
| 17 |
=(
| 8 |
| 17 |
| 9 |
| 17 |
| 1 |
| 19 |
=1×
| 1 |
| 19 |
=
| 1 |
| 19 |
(4)
| 3 |
| 7 |
| 2 |
| 5 |
| 3 |
| 5 |
| 4 |
| 7 |
=
| 6 |
| 35 |
| 12 |
| 35 |
=
| 18 |
| 35 |
(5)5×
| 4 |
| 5 |
=(5+5.5+1)×0.8
=11.5×0.8
=9.2;
(6)
| 4 |
| 9 |
| 3 |
| 4 |
| 7 |
| 16 |
| 1 |
| 4 |
=
| 4 |
| 9 |
| 3 |
| 4 |
| 3 |
| 16 |
=
| 4 |
| 9 |
| 9 |
| 16 |
=
| 1 |
| 4 |
点评:本题主要考查学生以及四则运算计算方法正确进行计算,以及正确运用简便方法解决问题的能力.
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