题目内容
递等式计算,能简便的用简便方法.
|
|
49×
| ||||||||||||||
|
(
|
(
|
分析:(1)(3)(4)(5)(6)运用乘法分配律解答,
(2)运用乘法交换律解答.
(2)运用乘法交换律解答.
解答:解:(1)
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(2)
×
×16,
=
×16×
,
=10×
,
=2
;
(3)49×
,
=48×
+1×
,
=11+
,
=11
;
(4)
×12+
,
=12×(
+
),
=12×1,
=12;
(5)(
+
)×12×35,
=
×12×35+
×12×35,
=9×35+12×7,
=315+84,
=499;
(6)(
+
+
)×48,
=
×48+
×48+
×48,
=42+8+32,
=82.
4 |
9 |
5 |
13 |
5 |
13 |
5 |
9 |
=(
4 |
9 |
5 |
9 |
5 |
13 |
=1×
5 |
13 |
=
5 |
13 |
(2)
5 |
8 |
2 |
7 |
=
5 |
8 |
2 |
7 |
=10×
2 |
7 |
=2
6 |
7 |
(3)49×
11 |
48 |
=48×
11 |
48 |
11 |
48 |
=11+
11 |
48 |
=11
11 |
48 |
(4)
34 |
35 |
12 |
35 |
=12×(
34 |
35 |
1 |
35 |
=12×1,
=12;
(5)(
3 |
4 |
1 |
5 |
=
3 |
4 |
1 |
5 |
=9×35+12×7,
=315+84,
=499;
(6)(
7 |
8 |
1 |
6 |
2 |
3 |
=
7 |
8 |
1 |
6 |
2 |
3 |
=42+8+32,
=82.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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