题目内容
我的算法好!
4.75×17.5+2.5×4.75 | 1.25×32×0.25 | 12.3+6.74+7.7+3.26 |
127.86×99+127.86 | 0.22×1.5+1.541÷2.3 | (5.15-3.25)×0.4+0.36. |
解:①4.75×17.5+2.5×4.75,
=4.75×(17.5+2.5),
=4.75×20,
=95;
②1.25×32×0.25,
=(1.25×8)×(0.25×4),
=10×1,
=1;
③12.3+6.74+7.7+3.26,
=(12.3+7.7)+(6.74+3.26),
=20+10,
=30;
④127.86×99+127.86,
=127.86×(99+1),
=127.86×100,
=12786;
⑤0.22×1.5+1.541÷2.3,
=0.33+0.67,
=1;
⑥(5.15-3.25)×0.4+0.36,
=1.9×0.4+0.36,
=0.76+0.36,
=1.12.
分析:①④运用乘法的分配律进行计算即可.
②运用乘法的结合律,交换律进行计算即可.
③运用加法的结合律及交换律进行计算即可.
⑤⑥根据四则混合运算的顺序进行计算即可.
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.
=4.75×(17.5+2.5),
=4.75×20,
=95;
②1.25×32×0.25,
=(1.25×8)×(0.25×4),
=10×1,
=1;
③12.3+6.74+7.7+3.26,
=(12.3+7.7)+(6.74+3.26),
=20+10,
=30;
④127.86×99+127.86,
=127.86×(99+1),
=127.86×100,
=12786;
⑤0.22×1.5+1.541÷2.3,
=0.33+0.67,
=1;
⑥(5.15-3.25)×0.4+0.36,
=1.9×0.4+0.36,
=0.76+0.36,
=1.12.
分析:①④运用乘法的分配律进行计算即可.
②运用乘法的结合律,交换律进行计算即可.
③运用加法的结合律及交换律进行计算即可.
⑤⑥根据四则混合运算的顺序进行计算即可.
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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