Class 8 Maths Chapter 1 Rational Numbers NCERT Solutions | CBSE 2026

 

📘 Class 8 Maths Chapter 1 – Rational Numbers

Looking for Class 8 Maths Chapter 1 Rational Numbers NCERT Solutions?
Here you will get clear explanations, important properties, solved examples, and exercise solutions in simple language.


🔹 Exercise 1.1 Solutions

Q1. Write the additive inverse of:

(i) 2/8
Additive inverse means the number which when added gives 0.
Answer: –2/8

(ii) –5/9
Answer: 5/9

(iii) 6/–5
Answer: 6/5


Q2. Find the reciprocal of:

(i) –8/9
Reciprocal = –9/8

(ii) 7/–3
Reciprocal = –3/7

(iii) –1
Reciprocal = –1


🔹 Exercise 1.2 Solutions

Q1. Verify closure property under addition:

Take 1/2 and 3/4

1/2 + 3/4

LCM of 2 and 4 = 4

1/2 = 2/4

Now add:
2/4 + 3/4 = 5/4

Since 5/4 is rational, closure property is verified.


Q2. Verify commutative property:

2/3 + 5/6

LCM = 6

2/3 = 4/6

4/6 + 5/6 = 9/6

Now reverse:

5/6 + 2/3

5/6 + 4/6 = 9/6

Both answers same. Property verified.


🔹 Important Properties of Rational Numbers

1️⃣ Closure Property
2️⃣ Commutative Property
3️⃣ Associative Property
4️⃣ Distributive Property


🔹 Important Formulas

  • Reciprocal of a/b = b/a

  • Additive inverse of a/b = –a/b

  • a × (b + c) = ab + ac


🔹 Tips for Exams

✔ Learn properties clearly
✔ Practice LCM carefully
✔ Revise multiplicative inverse concept


🔹 Conclusion

In this chapter, we learned:

  • What are rational numbers

  • Properties of rational numbers

  • How to find reciprocal

  • How to verify properties

Practice daily for better understanding.

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