题目内容
(2011?长汀县)
选用适当的方法计算: 41×10.1 |
37.5+45÷18×2.5 | ||||||||||||||||
(
|
(
|
分析:(1)运用乘法分配律简算;(2)(3)(4)按照先算乘除,再算加减,有小括号的先算括号里面的运算顺序计算.
解答:解:(1)41×10.1,
=41×(10+0.1),
=41×10+41×0.1,
=410+4.1,
=414.1;
(2)37.5+45÷18×2.5,
=37.5+2.5×2.5,
=37.5+6.25,
=43.75;
(3)(
+
)÷
+
,
=
×
+
,
=
+
,
=
;
(4)(
-
)×(
÷
),
=
×
,
=
.
=41×(10+0.1),
=41×10+41×0.1,
=410+4.1,
=414.1;
(2)37.5+45÷18×2.5,
=37.5+2.5×2.5,
=37.5+6.25,
=43.75;
(3)(
4 |
5 |
1 |
4 |
7 |
3 |
7 |
10 |
=
21 |
20 |
3 |
7 |
7 |
10 |
=
9 |
20 |
7 |
10 |
=
23 |
20 |
(4)(
2 |
3 |
1 |
3 |
8 |
3 |
4 |
5 |
=
1 |
3 |
10 |
3 |
=
10 |
9 |
点评:本题考查了四则混合运算的计算法则,计算时要看清楚能否运用简算的方法,若不能就按照运算顺序一步步求解.
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