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脱式计算5.3×1.7-0.7×5.33.4×2.81+0.66×28.15.6×0.125+2.4÷815-5.95×8.4÷3.58.01-÷0.12.32×49-

编辑:chaxungu时间:2026-04-27 07:38:35分类:小学数学题库

脱式计算
5.3×1.7-0.7×5.3

3.4×2.81+0.66×28.1
5.6×0.125+2.4÷815-5.95×8.4÷3.5
8.01-(0.43+7%)÷0.12.32×49-(10.26+8.24)
解:(1)5.3×1.7-0.7×5.3,
=5.3×(1.7-0.7),
=5.3×1,
=5.3;

(2)3.4×2.81+0.66×28.1,
=0.34×28.1+0.66×28.1,
=28.1×(0.34+0.66),
=28.1×1,
=28.1;

(3)5.6×0.125+2.4÷8,
=5.6×0.125+2.4×0.125,
=0.125×(5.6+2.4),
=0.125×8,
=1;


(4)15-5.95×8.4÷3.5,
=15-14.28,
=0.72;

(5)8.01-(0.43+7%)÷0.1,
=8.01-0.5÷0.1,
=8.01-5,
=3.01;

(6)2.32×49-(10.26+8.24)
=2.32×49-18.5,
=113.68-18.5,
=95.18.
分析:(1)据乘法分配律计算简便;
(2)把3.4×2.81变成0.34×28.1,再据乘法分配律计算简便;
(3)2.4÷8变成2.4×0.125,再据乘法分配律计算简便;
(4)(5)(6)据四则运算的顺序和法则计算.
点评:完成含有小数四则混合运算时,要注意小数点的对齐与小数点位置的变化以及运算定律的运用.