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Study Guide: CBSE Grade 8 Mathematics Exam Survival Guide
Source: https://www.fatskills.com/mcat/chapter/cbse-grade-8-mathematics-exam-survival-guide

CBSE Grade 8 Mathematics Exam Survival Guide

By Fatskills Exam Guides Team — the exam nerds behind 28,500+ quizzes and 2.1M practice questions across 500+ global exams.

⏱️ ~2 min read

Window: Annual Exam | Units: Algebra, Geometry, Mensuration, Data, Number Systems

Must-do topics (with how-to + examples)

  • Rational Numbers → Closure, additive inverse, distributive property.
    Ex: (2/3 + 4/5) × 1/2 → add first → multiply → simplify.
  • Exponents & Powers → Laws of exponents, scientific notation.
    Ex: 2⁵ ÷ 2³ = 2² = 4.
  • Algebraic Identities → (a+b)², (a−b)², a²−b², (x+a)(x+b).
    Ex: (x+5)(x−5) = x²−25.
  • Factorisation → Common factor, regrouping, identities.
  • Linear Equations in One Variable → Transpose terms step by step.
    Ex: 2x−7=13 → 2x=20 → x=10.
  • Mensuration → SA & volume of cube, cuboid, cylinder, cone, sphere.
    Ex: Volume of cone = ⅓πr²h.
  • Data Handling → Bar graph, pie chart, probability (favourable ÷ total).
  • Geometry → Quadrilaterals, polygons, parallel lines, angle sum property.

Top traps (avoid)

  • Forgetting to write units in area/volume.
  • Applying wrong identity (e.g., confusing (a+b)² with a²+b²).
  • Probability >1 or <0 (impossible!).
  • Linear equation step skips → careless errors.

Time split

Algebra + Equations 40% | Geometry/Mensuration 40% | Data 20%
Do 1-mark Qs first → long SA/volumes mid → data last.

Last-48h checklist

  • 20 Qs identities/factorisation.
  • 10 mensuration sums (cone, cylinder, sphere).
  • Revise probability basics + 1 pie chart.
  • One 3-hour past paper.

Quick facts / formulas

  • (a+b)² = a²+2ab+b² | (a−b)² = a²−2ab+b² | a²−b² = (a+b)(a−b)
  • SA sphere = 4πr² | Vol sphere = 4/3πr³
  • Probability = favourable ÷ total

Speed tactics

  • Write formula first → substitute → solve → box answer.
  • Check denominators in fractions (don’t drop).
  • Draw diagrams to visualise SA/volumes.

Exam-day mini-plan

  • Start with algebra Qs → mensuration → geometry proofs → data last.
  • Keep 15 min for unit/sign checks.