怎样简便就怎样计算31.2×99+31.24.6×10132.5-7.8-2.24×0.8×12.5×2.543.7÷2.5÷0.4.
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解决时间 2021-01-04 12:09
- 提问者网友:wodetian
- 2021-01-04 03:18
怎样简便就怎样计算 31.2×99+31.24.6×10132.5-7.8-2.24×0.8×12.5×2.543.7÷2.5÷0.4.
最佳答案
- 五星知识达人网友:雪起风沙痕
- 2021-01-04 03:33
解:(1)31.2×99+31.2,
=(99+1)×31.2,
=100×31.2,
=3120;
(2)4.6×101,
=4.6×(100+1),
=4.6×100+4.6×1,
=460+4.6,
=464.6;
(3)32.5-7.8-2.2,
=32.5-(7.8+2.2),
=32.5-10,
=22.5;
(4)4×0.8×12.5×2.5,
=(4×2.5)×(0.8×12.5),
=10×10,
=100;
(5)43.7÷2.5÷0.4,
=43.7÷(2.5×0.4),
=43.7÷1,
=43.7.解析分析:(1)(2)运用乘法分配律解答,(3)依据减法性质解答,(4)运用乘法交换律和结合律解答,(5)依据除法性质解答.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.
=(99+1)×31.2,
=100×31.2,
=3120;
(2)4.6×101,
=4.6×(100+1),
=4.6×100+4.6×1,
=460+4.6,
=464.6;
(3)32.5-7.8-2.2,
=32.5-(7.8+2.2),
=32.5-10,
=22.5;
(4)4×0.8×12.5×2.5,
=(4×2.5)×(0.8×12.5),
=10×10,
=100;
(5)43.7÷2.5÷0.4,
=43.7÷(2.5×0.4),
=43.7÷1,
=43.7.解析分析:(1)(2)运用乘法分配律解答,(3)依据减法性质解答,(4)运用乘法交换律和结合律解答,(5)依据除法性质解答.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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- 1楼网友:患得患失的劫
- 2021-01-04 04:32
你的回答很对
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