Notation is a system of written marks that stand for ideas, so people who know the system can read them without a long sentence. Music has notation — the notes, rests, and other signs on the lines. Maths has notation, like + or x². Chemistry, dance, and chess have their own systems too.

NotationNotation（記法、符號系統） is a system of written marks that stand for ideas是一套用書寫符號代表想法的系統，so people who know the system can read them without a long sentence懂這套系統的人不用長篇文字就能讀懂。Music has notation音樂有 notation（記譜法）——the notes, rests, and other signs on the lines那些音符、休止符，還有五線譜上的其他符號。Maths has notation數學也有 notation（記法），like + or x²像是 + 或 x²。Chemistry, dance, and chess化學、舞蹈、西洋棋 have their own systems too也都有自己的系統。

You usually say “musical notation” or “scientific notation” for the whole system (no plural). You can say “a notation” when you mean one way of writing something.

You usually say "musical notation" or "scientific notation" for the whole system講整套系統時，通常會說「musical notation」或「scientific notation」 (no plural)不會加複數。You can say "a notation"可以說「a notation」 when you mean one way of writing something如果你講的是某一種特定的寫法。

It is a school and specialist word, not a chatting word. Though actually, people sometimes say notation when they only mean scribbled notes. Careful speakers keep notation for a real system of signs, and notes for the words you jot down.

It這 is a school and specialist word是學校或專業領域用的字，not a chatting word不是聊天用字。Though actually但其實，people sometimes say notation when they only mean scribbled notes有時候人們講 notation，其實只是指隨手寫的筆記。Careful speakers keep notation for a real system of signs講究一點的人，會把 notation 留給真正的符號系統，and notes for the words you jot down把 notes（筆記）留給你隨手記下的文字。