after the decimal point; below the decimal
Refers to digits after the decimal point in a number; often used in mathematical or financial contexts.
計算結果はコンマ以下を切り捨ててください。
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.
彼の意見はコンマ以下の扱いを受けた。
His opinion was treated as beneath notice.