题目内容
正确、合理、灵活地计算.
(1)4.9+0.1-4.9+0.1
(2)
×3.7+5.2×0.5+1.1×50%
(3)12×(
+
-
)
(4)9.07×99+9.07
(5)
×
+
÷
(6)2009×5.
(1)4.9+0.1-4.9+0.1
(2)
1 |
2 |
(3)12×(
1 |
3 |
1 |
2 |
1 |
6 |
(4)9.07×99+9.07
(5)
5 |
8 |
11 |
10 |
3 |
8 |
10 |
11 |
(6)2009×5.
考点:运算定律与简便运算,整数、分数、小数、百分数四则混合运算
专题:运算顺序及法则,运算定律及简算
分析:(1)4.9+0.1-4.9+0.1,根据加、减法的运算性质简算;
(2)
×3.7+5.2×0.5+1.1×50%,把分数和百分数化成小数,再运用乘法分配律简算;
(3)12×(
+
-
),运用乘法分配律简算;
(4)9.07×99+9.07,运用乘法分配律简算;
(5)
×
+
÷
,把除数转化为乘它的倒数,再意义乘法分配律简算;
(6)2009×5.转化为:(2000+9)×5,运用乘法分配律简算.
(2)
1 |
2 |
(3)12×(
1 |
3 |
1 |
2 |
1 |
6 |
(4)9.07×99+9.07,运用乘法分配律简算;
(5)
5 |
8 |
11 |
10 |
3 |
8 |
10 |
11 |
(6)2009×5.转化为:(2000+9)×5,运用乘法分配律简算.
解答:
解:(1)4.9+0.1-4.9+0.1
=(4.9-4.9)+(0.1+0.1)
=0+0.2
=0.2;
(2)
×3.7+5.2×0.5+1.1×50%
=0.5×(3.7+5.2+1.1)
=0.5×10
=5;
(3)12×(
+
-
)
=12×
+12×
-12×
=4+6-2
=8;
(4)9.07×99+9.07
9.07×(99+1)
=9.07×100
=907;
(5)
×
+
÷
=(
+
)×
=1×
=
;
(6)2009×5
=2000×5+9×5
=10000+45
=10045.
=(4.9-4.9)+(0.1+0.1)
=0+0.2
=0.2;
(2)
1 |
2 |
=0.5×(3.7+5.2+1.1)
=0.5×10
=5;
(3)12×(
1 |
3 |
1 |
2 |
1 |
6 |
=12×
1 |
3 |
1 |
2 |
1 |
6 |
=4+6-2
=8;
(4)9.07×99+9.07
9.07×(99+1)
=9.07×100
=907;
(5)
5 |
8 |
11 |
10 |
3 |
8 |
10 |
11 |
=(
5 |
8 |
3 |
8 |
10 |
11 |
=1×
10 |
10 |
=
10 |
11 |
(6)2009×5
=2000×5+9×5
=10000+45
=10045.
点评:此题考查的目的是理解掌握加、减法的运算性质和乘法的运算定律,并且能够灵活运用这些运算性质和运算定律进行简便计算.
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