An exercise book or composition book is a notebook that is used in schools to copy down schoolwork and notes. A student will usually have a different exercise book for each separate lesson or subject . The exercise book format is different for some subjects : for the majority of subjects, the exercise book will contain lined paper with margin , but for other subjects such as mathmatics , the exercise book will contain squared paper to aid in the drawing of graphs, tables or other diagrams. Exercise books may act as a primary record of students' learning efforts. For younger pupils, books are often collected at the end of each lesson for review, scoring or grading. Loose worksheets may be pasted into the book so that they are bound with other work. In some schools, exercise books may be colour-coded depending on the subject. For example, Biology might be green and Algebra blue. The exercise book was also called version book historically, and is called khata in India ,co