题目内容
| 计算,能简便计算的要简便计算. (1)(9+92+93)×0.01 | (2)13.5×[1.5×(1.07+1.93)] | (3) |
| (4)(333+667)÷[63×( | (5) | (5)1998÷1998 |
解:(1)(9+92+93)×0.01
=[9+9×(9+9×9)]×0.01,
=[9+9×(9+81)]×0.01,
=[9+9×90]×0.01,
=[9+810]×0.01,
=819×0.01,
=8.19;
(2)13.5×[1.5×(1.07+1.93)]
=13.5×[1.5×3],
=13.5×4.5,
=60.75;
(3)
=
+
×(
-
),
=
+
×
,
=
+
,
=
+
,
=
;
(4)(333+667)÷[63×(
)]
=1000÷[63×
-63×
],
=1000÷[36-28],
=1000÷8,
=125;
(5)
+
+
+
+
=
+
+
+
+
,
=
-
+
-
+
-
+
-
+
-
,
=
-
,
=
;
(5)1998÷1998
,
=1998÷
,
=1998×
,
=
.
分析:算式(1)括号中的可根据乘法分配律计算;
算式(2)(3)根据四则混合运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号的里面的;
算式(4)中括号内的可根据乘法分配律计算;
算式(5)可根据
=
-
进行计算;
算式(6)可将带分数化为假分数后通过约分计算.
点评:完成本题要认真分析式中数的居特点及内在联系,然后运用合适的方法进行计算.
=[9+9×(9+9×9)]×0.01,
=[9+9×(9+81)]×0.01,
=[9+9×90]×0.01,
=[9+810]×0.01,
=819×0.01,
=8.19;
(2)13.5×[1.5×(1.07+1.93)]
=13.5×[1.5×3],
=13.5×4.5,
=60.75;
(3)
=
=
=
=
=
(4)(333+667)÷[63×(
=1000÷[63×
=1000÷[36-28],
=1000÷8,
=125;
(5)
=
=
=
=
(5)1998÷1998
=1998÷
=1998×
=
分析:算式(1)括号中的可根据乘法分配律计算;
算式(2)(3)根据四则混合运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号的里面的;
算式(4)中括号内的可根据乘法分配律计算;
算式(5)可根据
算式(6)可将带分数化为假分数后通过约分计算.
点评:完成本题要认真分析式中数的居特点及内在联系,然后运用合适的方法进行计算.
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