A study lesson dealing with the detergent concept was carried out at an upper secondary school in Cambodia after a number of teaching materials concerning with detergent were prepared for classroom activities. Through the pre-/post tests and questionnaires responded by students, the lesson study was evluated high appreciation and satisfactory. The activities prepared in the lesson study were applicable by students. It is also recommended that it can be appropriately introduced as part of curriculum at upper secondary schools in Cambodia and other developing countries which required teaching materials.
volume of water drop（水滴の体積）
surface tension of water（表面張力）
knowledge improvement of students（生徒の知識改善）