题目内容
|
(
|
1.25×0.4-0.25×40% | ||||||||||||||
7-
|
|
分析:(1)运用加法交换律与结合律简算;
(2)(3)运用乘法分配律简算;
(4)运用减法的性质简算;
(5)运用除法的性质简算.
(2)(3)运用乘法分配律简算;
(4)运用减法的性质简算;
(5)运用除法的性质简算.
解答:解:(1)
+
+
+
,
=(
+
)+(
+
),
=
+2,
=2
;
(2)(
+
+
)×12,
=
×12+
×12+
×12,
=9+8+2,
=19;
(3)1.25×0.4-0.25×40%,
=1.25×0.4-0.25×0.4,
=(1.25-0.25)×0.4,
=1×0.4,
=0.4;
(4)7-
-
-
,
=7-(
+
+
),
=7-1,
=6;
(5)
÷7-
÷7,
=(
-
)÷7,
=
÷7,
=
.
| 5 |
| 9 |
| 5 |
| 6 |
| 2 |
| 9 |
| 7 |
| 6 |
=(
| 5 |
| 9 |
| 2 |
| 9 |
| 5 |
| 6 |
| 7 |
| 6 |
=
| 7 |
| 9 |
=2
| 7 |
| 9 |
(2)(
| 3 |
| 4 |
| 2 |
| 3 |
| 1 |
| 6 |
=
| 3 |
| 4 |
| 2 |
| 3 |
| 1 |
| 6 |
=9+8+2,
=19;
(3)1.25×0.4-0.25×40%,
=1.25×0.4-0.25×0.4,
=(1.25-0.25)×0.4,
=1×0.4,
=0.4;
(4)7-
| 9 |
| 17 |
| 4 |
| 17 |
| 4 |
| 17 |
=7-(
| 9 |
| 17 |
| 4 |
| 17 |
| 4 |
| 17 |
=7-1,
=6;
(5)
| 11 |
| 15 |
| 4 |
| 15 |
=(
| 11 |
| 15 |
| 4 |
| 15 |
=
| 7 |
| 15 |
=
| 1 |
| 15 |
点评:完成此题,注意分析式中数据,运用运算定律或性质,进行简算.
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