题目内容
计算下面各题,能简算的要简算.
(1)10÷8+3.96×12.5%+2.04×
(2)6000-105×36
(3)85-84
÷7
(4)
÷[(
+
)×
]
(5)1
×3.6+3
×7
+3.6.
(1)10÷8+3.96×12.5%+2.04×
| 2 |
| 16 |
(2)6000-105×36
(3)85-84
| 7 |
| 8 |
(4)
| 4 |
| 15 |
| 4 |
| 7 |
| 4 |
| 21 |
| 7 |
| 12 |
(5)1
| 6 |
| 7 |
| 3 |
| 5 |
| 1 |
| 7 |
分析:(1)据乘法算式的性质将原式变为0.125×10+3.96×12.5%+2.04×0.125后再据分配律进行简便运算;
(2)根据分配律将105×36变为(100+5)×36再据减法性质进行计算;
(3)可先据分配律将式中84
÷7拆分为(84+
)÷7再据减法性质进行简便计算;
(4)可将括号中的算式据分配律进行简便计算;
(5)将据分配律进行简便计算.
(2)根据分配律将105×36变为(100+5)×36再据减法性质进行计算;
(3)可先据分配律将式中84
| 7 |
| 8 |
| 7 |
| 8 |
(4)可将括号中的算式据分配律进行简便计算;
(5)将据分配律进行简便计算.
解答:解:(1)10÷8+3.96×12.5%+2.04×
=1.25+3.96×12.5%+2.04×0.125,
=0.125×10+3.96×0.125+2.04×0.125,
=(10+3.96+2.04)×0.125,
=16×0.125,
=2;
(2)6000-105×36
=6000-(100+5)×36,
=6000-100×36-36×5,
=6000-3600-180,
=2220;
(3)85-84
÷7
=85-(84+
)÷7,
=85-84÷7-
÷7,
=85-12-
,
=72
;
(4)
÷[(
+
)×
]
=
÷[
×
+
×
],
=
÷[
+
],
=
×
,
=
;
(5)1
×3.6+3
×7
+3.6
=1
×3.6+3.6×7
+3.6,
=(1
+7
+1)×3.6,
=10×3.6,
=36.
| 2 |
| 16 |
=1.25+3.96×12.5%+2.04×0.125,
=0.125×10+3.96×0.125+2.04×0.125,
=(10+3.96+2.04)×0.125,
=16×0.125,
=2;
(2)6000-105×36
=6000-(100+5)×36,
=6000-100×36-36×5,
=6000-3600-180,
=2220;
(3)85-84
| 7 |
| 8 |
=85-(84+
| 7 |
| 8 |
=85-84÷7-
| 7 |
| 8 |
=85-12-
| 1 |
| 8 |
=72
| 7 |
| 8 |
(4)
| 4 |
| 15 |
| 4 |
| 7 |
| 4 |
| 21 |
| 7 |
| 12 |
=
| 4 |
| 15 |
| 4 |
| 7 |
| 7 |
| 12 |
| 4 |
| 21 |
| 7 |
| 12 |
=
| 4 |
| 15 |
| 1 |
| 3 |
| 1 |
| 9 |
=
| 4 |
| 15 |
| 9 |
| 4 |
=
| 3 |
| 5 |
(5)1
| 6 |
| 7 |
| 3 |
| 5 |
| 1 |
| 7 |
=1
| 6 |
| 7 |
| 1 |
| 7 |
=(1
| 6 |
| 7 |
| 1 |
| 7 |
=10×3.6,
=36.
点评:完成此类题目要认真分析式中据,根据式中数据的特点及内在联系选择合适的方法进行简便计算.
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