题目内容
计算,能简算的要简算,并写出主要过程.
306÷(201×47-9413)
÷[(
+
)×
]
(
×35+35×
)÷
2007×2009×(
+
)
53.7×5.3+537×0.37+53.7
+
+
+…+
.
306÷(201×47-9413)
| 1 |
| 5 |
| 2 |
| 3 |
| 1 |
| 5 |
| 1 |
| 13 |
(
| 3 |
| 8 |
| 5 |
| 8 |
| 5 |
| 7 |
2007×2009×(
| 1 |
| 2007×2008 |
| 1 |
| 2008×2009 |
53.7×5.3+537×0.37+53.7
| 2 |
| 1×2 |
| 2 |
| 2×3 |
| 2 |
| 3×4 |
| 2 |
| 2008×2009 |
分析:(1)先算括号内的乘法,再算扩阿红诶的剑法,最后算括号外的除法;
(2)先算小括号内的,再算中括号内的,最后算括号外的;
(3)运用乘法分配律的逆运算简算;
(4)运用乘法分配律简算;
(5)根据数字特点,把原式变为53.7×5.3+53.7×3.7+53.7,运用乘法分配律的逆运算简算;
(6)通过观察,每个分数的分子都是2,于是先把2拿出来,括号内的分数可以拆成两个分数相减的形式,然后通过加减相抵消的方法,得出结果.
(2)先算小括号内的,再算中括号内的,最后算括号外的;
(3)运用乘法分配律的逆运算简算;
(4)运用乘法分配律简算;
(5)根据数字特点,把原式变为53.7×5.3+53.7×3.7+53.7,运用乘法分配律的逆运算简算;
(6)通过观察,每个分数的分子都是2,于是先把2拿出来,括号内的分数可以拆成两个分数相减的形式,然后通过加减相抵消的方法,得出结果.
解答:解:(1)306÷(201×47-9413),
=306÷(9447-9413),
=306÷34,
=9;
(2)
÷[(
+
)×
],
=
÷[
×
],
=
÷
,
=
×15,
=3;
(3)
×35+35×
,
=(
+
)×35,
=1×35,
=35;
(4)2007×2009×(
+
),
=2007×2009×
+2007×2009×
,
=
+
,
=1+
+(1-
),
=2;
(5)53.7×5.3+537×0.37+53.7,
=53.7×5.3+53.7×3.7+53.7,
=(5.3+3.7+1)×53.7,
=10×53.7,
=537;
(6)
+
+
+…+
,
=2×(
+
+
+…+
),
=2×(1-
+
-
+
-
+…+
-
)
=2×(1-
)
=2×
=
.
=306÷(9447-9413),
=306÷34,
=9;
(2)
| 1 |
| 5 |
| 2 |
| 3 |
| 1 |
| 5 |
| 1 |
| 13 |
=
| 1 |
| 5 |
| 13 |
| 15 |
| 1 |
| 13 |
=
| 1 |
| 5 |
| 1 |
| 15 |
=
| 1 |
| 5 |
=3;
(3)
| 3 |
| 8 |
| 5 |
| 8 |
=(
| 3 |
| 8 |
| 5 |
| 8 |
=1×35,
=35;
(4)2007×2009×(
| 1 |
| 2007×2008 |
| 1 |
| 2008×2009 |
=2007×2009×
| 1 |
| 2007×2008 |
| 1 |
| 2008×2009 |
=
| 2009 |
| 2008 |
| 2007 |
| 2008 |
=1+
| 1 |
| 2008 |
| 1 |
| 2008 |
=2;
(5)53.7×5.3+537×0.37+53.7,
=53.7×5.3+53.7×3.7+53.7,
=(5.3+3.7+1)×53.7,
=10×53.7,
=537;
(6)
| 2 |
| 1×2 |
| 2 |
| 2×3 |
| 2 |
| 3×4 |
| 2 |
| 2008×2009 |
=2×(
| 1 |
| 1×2 |
| 1 |
| 2×3 |
| 1 |
| 3×4 |
| 1 |
| 2008×2009 |
=2×(1-
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 2008 |
| 1 |
| 2009 |
=2×(1-
| 1 |
| 2009 |
=2×
| 2008 |
| 2009 |
=
| 4016 |
| 2009 |
点评:此题考查了四则混合运算的运算顺序,以及运用运算定律或运算技巧简算的能力.
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