题目内容
(2010?扬州)
| 递等式计算(能简便的要简便) 25.3×12-33.46÷0.35 |
(
|
2.5×13×0.4 | ||||||||||||
|
9.34-(2.34+0.49) |
|
分析:(1)按运算顺序进行计算,先算乘除,再算减法;
(2)按运算顺序进行计算,先算括号内的,再算括号外的,注意通分和约分;
(3)运用乘法交换律和结合律简算;
(4)按运算顺序进行计算,先算小括号内的,再算中括号内的,最后算括号外的;
(5)先运用减法的性质去括号,再运用加法结合律简算;
(6)把
看作
×1,运用乘法分配律的逆运算简算.
(2)按运算顺序进行计算,先算括号内的,再算括号外的,注意通分和约分;
(3)运用乘法交换律和结合律简算;
(4)按运算顺序进行计算,先算小括号内的,再算中括号内的,最后算括号外的;
(5)先运用减法的性质去括号,再运用加法结合律简算;
(6)把
| 4 |
| 5 |
| 4 |
| 5 |
解答:解:(1)25.3×12-33.46÷0.35,
=303.6-95.6,
=208;
(2)(
+
)÷
,
=(
+
)÷
,
=
×24,
=29;
(3)2.5×13×0.4,
=(2.5×0.4)×13,
=1×13,
=13;
(4)
÷[(
+
)×
],
=
÷[(
+
)×
],
=
÷[
×
],
=
÷
,
=
×
,
=
;
(5)9.34-(2.34+0.49),
=(9.34-2.34)-0.49,
=7-0.49,
=6.51;
(6)
+
×19,
=(1+19)×
,
=20×
,
=16.
=303.6-95.6,
=208;
(2)(
| 3 |
| 8 |
| 5 |
| 6 |
| 1 |
| 24 |
=(
| 9 |
| 24 |
| 20 |
| 24 |
| 1 |
| 24 |
=
| 29 |
| 24 |
=29;
(3)2.5×13×0.4,
=(2.5×0.4)×13,
=1×13,
=13;
(4)
| 8 |
| 9 |
| 2 |
| 5 |
| 1 |
| 10 |
| 3 |
| 4 |
=
| 8 |
| 9 |
| 4 |
| 10 |
| 1 |
| 10 |
| 3 |
| 4 |
=
| 8 |
| 9 |
| 1 |
| 2 |
| 3 |
| 4 |
=
| 8 |
| 9 |
| 3 |
| 8 |
=
| 8 |
| 9 |
| 8 |
| 3 |
=
| 64 |
| 27 |
(5)9.34-(2.34+0.49),
=(9.34-2.34)-0.49,
=7-0.49,
=6.51;
(6)
| 4 |
| 5 |
| 4 |
| 5 |
=(1+19)×
| 4 |
| 5 |
=20×
| 4 |
| 5 |
=16.
点评:此题综合考查四则混合运算的法则和顺序,同时考查了学生运用运算性质、定律进行简算的能力.
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