SI units (marks for units)

A number in a Science or Maths answer needs its unit. "154" alone does not say whether it means square centimetres or square metres. The unit is part of what the answer says.

Are marks cut for not writing units?

No single rule covers every paper. The marking scheme for each question decides. In CBSE's 2026-27 Maths Standard sample scheme, Question 24 ends with a half-mark answer line. That line is written with its unit: 154 cm².

A sample marking scheme in CBSE's 2021 handbook on assessment says method marks are not lost for "errors in units". Method marks are the marks for a correct way of working. The handbook is guidance for people who set papers, so the paper's own scheme still decides.

What does ICSE Physics say?

CISCE states a rule in its ICSE Physics syllabus, edition for the 2028 exam. It says "only SI Units are to be used" for answering questions, unless a question says otherwise. In its report on the 2025 paper, the examiners list "Missed or used the incorrect unit" on one question. Their advice to candidates reads: "Pay attention to writing correct units for all physical quantities".

Units sit beside significant figures in ICSE practical work. Our post on how ICSE Physics numericals are marked shows where unit mark-loss appears in real answers.

About the author

Mohit Sardana

Chief Architect

An engineer (B.Tech, Computer Science) with over 20 years of preparing students for entrance exams, including as Dean at FIITJEE and Vice-President at Aakash. He is the chief architect of the TRUpreBoards evaluation engine.

Mohit Sardana on LinkedIn