also: ネズミざん
noun
geometric progression; exponential growth
Refers to the mathematical concept of geometric progression, often illustrated by the rapid multiplication of mice. Used in contexts like 鼠算的に増える (increase exponentially).
鼠算で計算すると、わずか数か月で莫大な数になる。
If you calculate it as a geometric progression, it becomes an enormous number in just a few months.
noun
proliferation; multiplying like rats
Figurative use emphasizing rapid, uncontrolled increase, often with a negative connotation. Common in phrases like 鼠算的に増える.
放置された空き家が鼠算的に増えている。
Abandoned houses are proliferating like rats.
Mixed kana-kanji spelling; easier to read for learners.
Katakana-kanji spelling; sometimes used for emphasis or in informal writing.
指数関数的 is a more formal, mathematical term for 'exponential', while 鼠算 carries a vivid, figurative image of rapid multiplication.
Compound of 鼠 (nezumi, 'mouse/rat') and 算 (zan, 'calculation'), referring to the rapid multiplication of rodents as a metaphor for geometric progression. The exact historical origin is uncertain, but it is a well-established idiomatic term.