Class 8 Mathematics — Chapter 1: Rational Numbers
72 practice questions · 24 Easy · 24 Medium · 24 Hard
Practise Class 8 Mathematics Chapter 1, "Rational Numbers", with 72 NCERT-aligned multiple-choice questions. The set is split into 24 Easy, 24 Medium and 24 Hard questions, so you can warm up on the fundamentals and then push into the exam-level problems that separate top scorers in CBSE Board exams.
"Rational Numbers" is one of the chapters where problem-solving speed, formula recall and step-by-step reasoning really pays off. Each MCQ on this chapter is timed and uses exam-grade marking (+2 correct, −1 wrong, 0 skipped), training the same accuracy-under-pressure that real papers demand. Every question carries a short explanation, so a wrong answer becomes a quick lesson rather than a dead end — the fastest way to close gaps before a test.
Use this chapter as targeted revision: attempt the Easy set first to confirm your basics on Rational Numbers, then move to Medium and Hard to test application and problem-solving. Your accuracy, streaks and XP save automatically, and the chapter feeds into your overall Class 8 Mathematics mastery score. A few sample questions are shown below; sign in free to practise all 72.
Key concepts: Rational Numbers (Class 8 Mathematics)
This chapter studies rational numbers and their properties under the basic operations, the role of 0 and 1, and how to find rational numbers between any two given ones.
- Rational number
- A number that can be written as p/q where p and q are integers and q ≠ 0.
- Closure & commutativity
- Rationals are closed under +, − and ×; addition and multiplication are commutative and associative, but subtraction and division are not.
- Identity & inverse
- 0 is the additive identity and 1 the multiplicative identity; the additive inverse of a/b is −a/b and the reciprocal is b/a.
- Distributive law
- a × (b + c) = a×b + a×c, used to simplify calculations.
- Rationals between two rationals
- There are infinitely many rationals between any two; the mean (average) gives one easily.
Key formulas — Rational Numbers
💡 Exam tips for Rational Numbers
- Use the average (a+b)/2 to find a rational number between two given rationals — repeat for more.
- Remember subtraction and division are NOT commutative or associative for rationals.
Sample questions
The multiplicative identity for rational numbers is:
Any rational number multiplied by 1 remains unchanged.
Find the sum: 2/3 + (−5/6).
LCM of 3 and 6 is 6. So 2/3 = 4/6. Then 4/6 + (−5/6) = (4 − 5)/6 = −1/6.
The product of two rational numbers is −16/9. If one of them is −4/3, the other is:
Other = (−16/9) ÷ (−4/3) = (−16/9) × (−3/4) = 4/3.
Rational Numbers — FAQs
What are the key concepts in Class 8 Mathematics Rational Numbers?+
This chapter studies rational numbers and their properties under the basic operations, the role of 0 and 1, and how to find rational numbers between any two given ones. Key ideas include Rational number, Closure & commutativity, Identity & inverse, Distributive law, Rationals between two rationals.
What does Class 8 Mathematics Chapter 1 (Rational Numbers) cover on XamBaaz?+
It covers 72 NCERT-aligned MCQs on "Rational Numbers" — 24 Easy, 24 Medium and 24 Hard — each with a timed quiz and an instant explanation, suitable for CBSE Board exams.
Are these "Rational Numbers" questions free to practise?+
Yes — sign in with Google to practise "Rational Numbers" free. Full unlimited access is ₹999/year (limited-time launch price), with no per-chapter charges.
How should I revise "Rational Numbers" for the exam?+
Start with the Easy quiz to confirm your fundamentals, then attempt Medium and Hard for application-level practice. Review each explanation, retry the questions you miss, and track your accuracy on this chapter until it is consistently high.
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