题目内容
计算下面各题,能简算的要简算.
×
+
÷9
[
-(
+
)]×
213×
÷
-
÷
×
+
÷
.
| 7 |
| 18 |
| 8 |
| 9 |
| 7 |
| 18 |
[
| 13 |
| 8 |
| 5 |
| 8 |
| 5 |
| 7 |
| 3 |
| 4 |
213×
| 9 |
| 212 |
| 6 |
| 13 |
| 9 |
| 26 |
| 3 |
| 4 |
| 5 |
| 8 |
| 3 |
| 5 |
| 3 |
| 7 |
| 2 |
| 5 |
| 7 |
| 3 |
考点:分数的四则混合运算,分数的简便计算
专题:运算顺序及法则
分析:(1)把除以9化成乘以
,再运用乘法的分配律进行简算;
(2)先去小括号,再算中括号里的减法,最后算括号外的乘法;
(3)把213化成(212+1),再运用乘法的分配律进行简算;
(4)先算除法,再算减法;
(5)把除以
化成乘以
,再运用乘法的分配律进行简算.
| 1 |
| 9 |
(2)先去小括号,再算中括号里的减法,最后算括号外的乘法;
(3)把213化成(212+1),再运用乘法的分配律进行简算;
(4)先算除法,再算减法;
(5)把除以
| 7 |
| 3 |
| 3 |
| 7 |
解答:
解:(1)
×
+
÷9
=
×
+
×
=
×(
+
)
=
×1
=
;
(2)[
-(
+
)]×
=[
-
-
)]×
=[1-
]×
=
×
=
;
(3)213×
=(212+1)×
=212×
+1×
=9+
=9
;
(4)
÷
-
÷
=
-
=
;
(5)
×
+
÷
=
×
+
×
=(
+
)×
=1×
=
.
| 7 |
| 18 |
| 8 |
| 9 |
| 7 |
| 18 |
=
| 7 |
| 18 |
| 8 |
| 9 |
| 7 |
| 18 |
| 1 |
| 9 |
=
| 7 |
| 18 |
| 8 |
| 9 |
| 1 |
| 9 |
=
| 7 |
| 18 |
=
| 7 |
| 18 |
(2)[
| 13 |
| 8 |
| 5 |
| 8 |
| 5 |
| 7 |
| 3 |
| 4 |
=[
| 13 |
| 8 |
| 5 |
| 8 |
| 5 |
| 7 |
| 3 |
| 4 |
=[1-
| 5 |
| 7 |
| 3 |
| 4 |
=
| 2 |
| 7 |
| 3 |
| 4 |
=
| 3 |
| 14 |
(3)213×
| 9 |
| 212 |
=(212+1)×
| 9 |
| 212 |
=212×
| 9 |
| 212 |
| 9 |
| 212 |
=9+
| 9 |
| 212 |
=9
| 9 |
| 212 |
(4)
| 6 |
| 13 |
| 9 |
| 26 |
| 3 |
| 4 |
| 5 |
| 8 |
=
| 4 |
| 3 |
| 6 |
| 5 |
=
| 2 |
| 15 |
(5)
| 3 |
| 5 |
| 3 |
| 7 |
| 2 |
| 5 |
| 7 |
| 3 |
=
| 3 |
| 5 |
| 3 |
| 7 |
| 2 |
| 5 |
| 3 |
| 7 |
=(
| 3 |
| 5 |
| 2 |
| 5 |
| 3 |
| 7 |
=1×
| 3 |
| 7 |
=
| 3 |
| 7 |
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
练习册系列答案
相关题目