Question

1.25×5.7+4.3×3.56应该怎么简便算法？

Answer 1

1.25×5.7+4.3×3.56的简便计算如下：

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1.25×5.7+4.3×3.56  %把5.7写成(10-4.3)

=1.25×(10-4.3)+4.3×3.56   %使用乘法分配率计算1.25×(10-4.3)和使用乘法交换律计算1.25×4.3

=12.5-4.3×1.25+4.3×3.56 %提取公因数4.3

=12.5+4.3×(3.56-1.25)  %把(3.56-1.25)改写成(2+0.3+0.01)

=12.5+4.3×(2+0.3+0.01) %使用乘法分配率计算4.3×(2+0.3+0.01)

=12.5+8.6+1.29+0.043

=22.433

Answer 2

1.25×5.7+4.3×3.56
1.25×5.7=7.125
4.3×3.56=15.308
原式=7.125+15.308=22.433

Answer 3

1.25×5.7+4.3×3.56
=7.125+15.308
=22.433