题目内容
(1)
|
(2)3.25×27+73×3.25 | (3)
|
分析:(1)运用加法交换律和结合律简算;
(2)运用乘法分配律简算;
(3)运用加法结合律和减法的性质简算.
(2)运用乘法分配律简算;
(3)运用加法结合律和减法的性质简算.
解答:解:(1)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2;
(2)3.25×27+73×3.25,
=3.25×(27+73),
=3.25×100,
=325;
(3))
-
+
-
,
=(
+
)-(
+
),
=1-
,
=
.
| 11 |
| 12 |
| 5 |
| 8 |
| 3 |
| 8 |
| 1 |
| 12 |
=(
| 11 |
| 12 |
| 1 |
| 12 |
| 5 |
| 8 |
| 3 |
| 8 |
=1+1,
=2;
(2)3.25×27+73×3.25,
=3.25×(27+73),
=3.25×100,
=325;
(3))
| 7 |
| 9 |
| 1 |
| 8 |
| 2 |
| 9 |
| 3 |
| 8 |
=(
| 7 |
| 9 |
| 2 |
| 9 |
| 1 |
| 8 |
| 3 |
| 8 |
=1-
| 1 |
| 2 |
=
| 1 |
| 2 |
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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