CBSE Board Exam

Marking scheme assigns a fixed proportion of the allotted marks to particular knowledge,

understanding and/or skill.

While solving a problem, writing a formula, substituting values in the formula, simplification,
application of BODMAS rule to simplify,
Writing proven statements as reasons are essential parts

of the solution that fetch marks. Students could make a mistake in any of the steps mentioned.

A small mistake in any of the steps could lead to a deduction of marks. For example,

a mistake as minor as assigning the wrong sign to a numerical while substitution or simplification

might give the wrong answer.