题目内容
计算下面各题,能简便计算的要简便计算.
8×0.56×12.5 | 6.25+
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|
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分析:(1)运用乘法交换律简算;
(2)运用加法交换律和结合律简算;
(3)运用乘法分配律简算;
(4)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的除法.
(2)运用加法交换律和结合律简算;
(3)运用乘法分配律简算;
(4)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的除法.
解答:解:(1)8×0.56×12.5,
=8×12.5×0.56,
=100×0.56,
=56;
(2)6.25+
-2.25+
,
=(6.25-2.25)+(
+
),
=4+1,
=5;
(3)
×
+
×
,
=
×(
+
),
=
×1,
=
;
(4)
÷[(
+
)×
],
=
÷[
×
],
=
÷
,
=5.
=8×12.5×0.56,
=100×0.56,
=56;
(2)6.25+
5 |
7 |
2 |
7 |
=(6.25-2.25)+(
2 |
7 |
5 |
7 |
=4+1,
=5;
(3)
5 |
11 |
3 |
7 |
4 |
7 |
5 |
11 |
=
5 |
11 |
3 |
7 |
4 |
7 |
=
5 |
11 |
=
5 |
11 |
(4)
1 |
3 |
2 |
3 |
1 |
5 |
1 |
13 |
=
1 |
3 |
13 |
15 |
1 |
13 |
=
1 |
3 |
1 |
15 |
=5.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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