算数

1. Origins, structure, and basic meaning

• Structure: 算数(さんすう) is a noun for arithmetic, the study and use of numbers and basic calculations.
• Basic usage: The school subject appears in 学校で算数を勉強する, while a problem in that subject is 算数の問題.

2. Common pitfalls and similar expressions

• Subject and problem
  • 算数 names the subject as a whole, while 算数の問題 is an individual problem solved with that knowledge.
• Place and object
  • Use 学校で for the place of study and 算数を for the subject being studied.