题目内容
简算:
| 84× | 86× | 0.25×32×0.125 |
| 41×101 | 56×99 | 1200-197. |
解:(1)84×
,
=(85-1)×
,
=85×
-
,
=3-
,
=2
;
(2)86×
,
=(85+1)×
,
=3+
,
=3
;
(3)0.25×32×0.125,
=0.25×4×8×0.125,
=(0.25×4)×(8×0.125),
=1×1,
=1;
(4)41×101,
=41×(100+1),
=4100+41,
=4141;
(5)56×99,
=56×(100-1),
=5600-56,
=5544;
(6)1200-197,
=1200-(200-3),
=1200-200+3,
=1003.
分析:(1)把84看作85-1,运用乘法分配律简算;
(2)把86看作85+1,运用乘法分配律简算;
(3)把32看作4×8,运用乘法结合律简算;
(4)把101看作100+1,运用乘法分配律简算;
(5)把99看作100-1,运用乘法分配律简算;
(6)把197看作200-3,运用减法的性质简算.
点评:完成此题,应注意分析式中数据,运用合适的简便方法计算.
=(85-1)×
=85×
=3-
=2
(2)86×
=(85+1)×
=3+
=3
(3)0.25×32×0.125,
=0.25×4×8×0.125,
=(0.25×4)×(8×0.125),
=1×1,
=1;
(4)41×101,
=41×(100+1),
=4100+41,
=4141;
(5)56×99,
=56×(100-1),
=5600-56,
=5544;
(6)1200-197,
=1200-(200-3),
=1200-200+3,
=1003.
分析:(1)把84看作85-1,运用乘法分配律简算;
(2)把86看作85+1,运用乘法分配律简算;
(3)把32看作4×8,运用乘法结合律简算;
(4)把101看作100+1,运用乘法分配律简算;
(5)把99看作100-1,运用乘法分配律简算;
(6)把197看作200-3,运用减法的性质简算.
点评:完成此题,应注意分析式中数据,运用合适的简便方法计算.
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