《比例对数表》和《比例四线新表》分别给出了1～10000的六位对数表和六位三角函数对数表。 书中把今天所说的“对数”称为“比例数”或“假数”，并简单解释了把乘除运算化为加减运算的道理。 这是对数方法在中国的首次介绍。 对数是17世纪最重要的发现之一，它有效地简化了繁重的计算工作。 在对数、解析几何和微积分这三种当时西方最重要的数学方法中，也只有对数比较及时地 …

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