對數

Etymology
The term originates from the historical use of logarithm tables as the standard computational device. The character signifies the one-to-one correspondence and pairwise appearance of a number 真數 ("true value", i.e. the antilogarithm) and its logarithm (sometimes termed 借數 or 假數, "borrowed value, substitute value") in such tables. For example,

Noun

 * 1)  logarithm