题目内容
(1)0.125×0.32×5=
(2)1.25×0.25÷
=
(3)0.25×1.25÷
=
(4)35000÷28×8=
(5)222×555=
(6)8888×875×
=
(7)0.125×0.25×0.5×64=
(8)1993÷1993
=
(2)1.25×0.25÷
| 1 |
| 16 |
(3)0.25×1.25÷
| 1 |
| 64 |
(4)35000÷28×8=
(5)222×555=
(6)8888×875×
| 1 |
| 7 |
(7)0.125×0.25×0.5×64=
(8)1993÷1993
| 1993 |
| 1995 |
分析:(1)根据乘法交换律和结合律进行计算;
(2)根据乘法交换律和结合律进行计算;
(3)根据乘法交换律和结合律进行计算;
(4)根据除法的性质进行简算;
(5)222=2×111,555=5×111,然后再根据乘法交换律和结合律进行计算;
(6)根据乘法交换律和结合律进行计算;
(7)根据乘法交换律和结合律进行计算;
(8)1993
,化成假分数,分子根据乘法分配律进行计算,然后再根据分数的除法的计算方法,进行计算.
(2)根据乘法交换律和结合律进行计算;
(3)根据乘法交换律和结合律进行计算;
(4)根据除法的性质进行简算;
(5)222=2×111,555=5×111,然后再根据乘法交换律和结合律进行计算;
(6)根据乘法交换律和结合律进行计算;
(7)根据乘法交换律和结合律进行计算;
(8)1993
| 1993 |
| 1995 |
解答:解:
(1)0.125×0.32×5,
=0.125×(0.8×0.4)×5,
=(0.125×0.8)×(0.4×5),
=0.1×2,
=0.2;
(2)1.25×0.25÷
,
=1.25×0.25×16,
=1.25×0.25×(8×2),
=(1.25×8)×(0.25×2),
=10×0.5,
=5;
(3)0.25×1.25÷
,
=0.25×1.25×64,
=0.25×1.25×(8×8),
=(0.25×8)×(1.25×8),
=2×10,
=20;
(4)35000÷28×8,
=35000÷(7×4)÷8,
=35000÷7÷4×8,
=(35000÷7)×(8÷4),
=5000×2,
=10000;
(5)222×555,
=(2×111)×(5×111),
=(2×5)×(111×111),
=10×12321,
=123210;
(6)8888×875×
,
=8888×(875×
),
=8888×125,
=(8×1111)×125,
=1111×(8×125),
=1111×1000,
=1111000;
(7)0.125×0.25×0.5×64,
=0.125×0.25×0.5×(8×4×2),
=(0.125×8)×(0.25×4)×(0.5×2),
=1×1×1,
=1;
(8)1993÷1993
,
=1993÷
,
=1993÷
,
=1993÷
,
=1993×
,
=
.
(1)0.125×0.32×5,
=0.125×(0.8×0.4)×5,
=(0.125×0.8)×(0.4×5),
=0.1×2,
=0.2;
(2)1.25×0.25÷
| 1 |
| 16 |
=1.25×0.25×16,
=1.25×0.25×(8×2),
=(1.25×8)×(0.25×2),
=10×0.5,
=5;
(3)0.25×1.25÷
| 1 |
| 64 |
=0.25×1.25×64,
=0.25×1.25×(8×8),
=(0.25×8)×(1.25×8),
=2×10,
=20;
(4)35000÷28×8,
=35000÷(7×4)÷8,
=35000÷7÷4×8,
=(35000÷7)×(8÷4),
=5000×2,
=10000;
(5)222×555,
=(2×111)×(5×111),
=(2×5)×(111×111),
=10×12321,
=123210;
(6)8888×875×
| 1 |
| 7 |
=8888×(875×
| 1 |
| 7 |
=8888×125,
=(8×1111)×125,
=1111×(8×125),
=1111×1000,
=1111000;
(7)0.125×0.25×0.5×64,
=0.125×0.25×0.5×(8×4×2),
=(0.125×8)×(0.25×4)×(0.5×2),
=1×1×1,
=1;
(8)1993÷1993
| 1993 |
| 1995 |
=1993÷
| 1993×1995+1993 |
| 1995 |
=1993÷
| 1993×(1995+1) |
| 1995 |
=1993÷
| 1993×1996 |
| 1995 |
=1993×
| 1995 |
| 1993×1996 |
=
| 1995 |
| 1996 |
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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