コンマ以い下か

expression

after the decimal point; below the decimal

Refers to digits after the decimal point in a number; often used in mathematical or financial contexts.

• 計けい算さん結けっ果かはコンマ以い下かを切きり捨すててください。

  Please round down the digits after the decimal point in the calculation result.

expression, noun which may take the genitive case particle 'no'

of no account; beneath notice

Idiomatic figurative use: something so trivial it is not worth considering, like digits after the decimal point.