式

1. Origins, structure, and basic meaning

• Structure: 式, read しき, can mean a ceremony with an established procedure or a mathematical formula.
• Basic usage: In 卒業式は午前十時に始まる。, the graduation ceremony begins at ten in the morning.

2. Common pitfalls and similar expressions

• Ceremony and formula
  • 卒業式 is a ceremony marking graduation, while 値を式に入れて refers to substituting values into a mathematical formula.