用递等式计算.(能简便计算的用简便方法计算) 53.2+6.3-6.3÷0.7(2.5-0.25-0.025)×4(50-16.9÷13)×0.61.25×(0.8+4)×250.25×1.25×3.235.7×5.6-5.6+65.3×5.6.
网友回答
解:(1)53.2+6.3-6.3÷0.7,
=53.2+6.3-9,
=50.5;
(2)(2.5-0.25-0.025)×4,
=2.5×4-0.25×4-0.025×4,
=10-1-0.1,
=8.9;
(3)(50-16.9÷13)×0.6,
=(50-1.3)×0.6,
=48.7×0.6,
=29.22;
(4)1.25×(0.8+4)×25,
=1.25×4.8×25,
=150;
(5)0.25×1.25×3.2,
=0.25×1.25×4×0.8,
=(0.25×4)×(1.25×0.8),
=1×1,
=1;
(6)35.7×5.6-5.6+65.3×5.6,
=(35.7-1+65.3)×5.6,
=100×5.6,
=560.
解析分析:(1)先算除,再算加减;(2)利用乘法的分配律进行计算;(3)先算小括号里的除,然后再算括号里的减,最后算括号外面的乘;(4)先算括号里面的加,再算括号外的乘;(5)把3.2分成4×0.8,然后乘用乘法的结合律进行计算;(6)利用乘法的分配律的逆运算,同时提取5.6,然后进行计算.
点评:此题考查学生灵活运用运算定律简算的能力,以及对运算顺序的考查.