题目内容
能简算的要简算
|
(
|
| ||||||||||||||
|
(
|
99×
|
分析:(1)根据乘法交换律和结合律进行计算;
(2)、(3)、(4)、(5)、(6)根据乘法分配律进行即可.
(2)、(3)、(4)、(5)、(6)根据乘法分配律进行即可.
解答:解:
(1)
×
×13×11,
=(
×11)×(
×13),
=10×1,
=10;
(2)(
+
)×
,
=
×
+
×
,
=
+1,
=
;
(3)
×21+28×
,
=
×(21+28),
=
×49,
=13;
(4)
-
×
,
=
×(1-
),
=
×
,
=
;
(5)(
+
)×32,
=
×32+
×32,
=24+20,
=44;
(6)99×
,
=(98+1)×
,
=98×
+1×
,
=5+
,
=5
.
(1)
| 10 |
| 11 |
| 1 |
| 13 |
=(
| 10 |
| 11 |
| 1 |
| 13 |
=10×1,
=10;
(2)(
| 4 |
| 5 |
| 3 |
| 10 |
| 10 |
| 3 |
=
| 4 |
| 5 |
| 10 |
| 3 |
| 3 |
| 10 |
| 10 |
| 3 |
=
| 8 |
| 3 |
=
| 11 |
| 3 |
(3)
| 13 |
| 49 |
| 13 |
| 49 |
=
| 13 |
| 49 |
=
| 13 |
| 49 |
=13;
(4)
| 4 |
| 5 |
| 4 |
| 5 |
| 5 |
| 6 |
=
| 4 |
| 5 |
| 5 |
| 6 |
=
| 4 |
| 5 |
| 1 |
| 6 |
=
| 2 |
| 15 |
(5)(
| 3 |
| 4 |
| 5 |
| 8 |
=
| 3 |
| 4 |
| 5 |
| 8 |
=24+20,
=44;
(6)99×
| 5 |
| 98 |
=(98+1)×
| 5 |
| 98 |
=98×
| 5 |
| 98 |
| 5 |
| 98 |
=5+
| 5 |
| 98 |
=5
| 5 |
| 98 |
点评:考查了运算定律与简便运算.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.
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