题目内容
简便计算.
65.5×3.2+6.55×58+65.5
99×
32×1.25×0.25.
65.5×3.2+6.55×58+65.5
99×
97 |
98 |
32×1.25×0.25.
考点:运算定律与简便运算
专题:运算定律及简算
分析:①把6.55×58=65.5×5.8,然后根据乘法分配律,计算即可;
②把99拆分为98+1,然后根据乘法分配律,计算即可;
③把32拆分为4×8,然后根据乘法交换律及结合律计算;即可得解.
②把99拆分为98+1,然后根据乘法分配律,计算即可;
③把32拆分为4×8,然后根据乘法交换律及结合律计算;即可得解.
解答:
解:①65.5×3.2+6.55×58+65.5
=65.5×3.2+65.5×5.8+65.5
=65.5×(3.2+5.8+1)
=65.5×10
=655
②99×
=(98+1)×
=98×
+
=97+
=97
③32×1.25×0.25
=(4×8)×1.25×0.25
=(4×0.25)×(1.25×8)
=1×10
=10
=65.5×3.2+65.5×5.8+65.5
=65.5×(3.2+5.8+1)
=65.5×10
=655
②99×
97 |
98 |
=(98+1)×
97 |
98 |
=98×
97 |
98 |
97 |
98 |
=97+
97 |
98 |
=97
97 |
98 |
③32×1.25×0.25
=(4×8)×1.25×0.25
=(4×0.25)×(1.25×8)
=1×10
=10
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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