Class 8 NCERT (CBSE) Mathematics Solutions | Chapter 1, Rational Numbers (Exercise 1.1)

Class VIII, CBSE Mathematics

Chapter 1, Rational Numbers (NCERT Math Solutions)  

Exercise 1.1 Solutions (Rational Numbers)

Q.1: Using appropriate properties find:

Ans:

(i) Method - 1

Method - 2

(ii) Method - 1

Method - 2

Q.2: Write the additive inverse of each of the following:

Ans:

Q.3: Verify that −(−x) = x for.

Ans: 

Q.4: Find the multiplicative inverse of the following.

Ans:

Q.5: Name the property under multiplication used in each of the following:

Ans:

(i) 1 is the multiplicative identity.

(ii) Commutativity

(iii) Multiplicative inverse

Q.7: Tell what property allows you to compute.

Ans:

No, for multiplicative inverse, the product will be 1. But, here the product is not 1.

Since the product is 1 so, the answer is yes.

Q.10: Write:

(i) The rational number that does not have a reciprocal.

(ii) The rational numbers that are equal to their reciprocals.

(iii) The rational number that is equal to its negative.

Ans:

 (i) Zero has no reciprocal.

(ii) The reciprocals of 1 is 1. Therefore, 1 is the rational number which is equal to its reciprocal.

(iii) Zero is the rational number that is equal to its negative.

Q.11: Fill in the blanks.

(i) Zero has __________ reciprocal.

Ans: no

(ii) The numbers __________ and __________ are their own reciprocals

Ans: 1, -1

(iii) The reciprocal of − 5 is __________.

Ans: x

(v) The product of two rational numbers is always a __________.

Ans: rational number

(vi) The reciprocal of a positive rational number is __________.

Ans: positive rational number.

 Also Read 

• Class 8 NCERT Mathematics Guide: Rational Numbers - properties and important points