noun, noun or participle which takes 'suru'
decrease in number; reduction in quantity
General term for a numerical decrease; can be used as a noun or with する to mean 'to decrease in number'.
今年は応募者の減数が目立つ。
This year, a decrease in the number of applicants is noticeable.
会員が減数している。
The membership is decreasing in number.
noun, noun or participle which takes 'suru'
subtrahend
Mathematics term: the number that is subtracted from another (the minuend).
引き算では、減数は引く方の数です。
In subtraction, the subtrahend is the number being subtracted.