- Natural Number and Whole Numbers
- |
- Integers
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- Rational Numbers
- |
- Properties of Rational Numbers
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- Additive Identity/Role of Zero
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- Multiplicative identity/Role of one
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- Additive Inverse
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- Reciprocal or multiplicative inverse
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- How to Represent Rational Number on the Number Line
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- Rational Numbers between Two Rational Numbers

In this page we have *Important questions for rational Numbers Class 8 CBSE*
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Write the additive inverse of each of the following:

- 1
- $\frac {-1}{9}$
- $ \frac {-2}{3}$
- 2
- $\frac {-9}{1}$

(i) 1

Additive inverse = -1

(ii) $\frac {-1}{9}$

Additive inverse = $\frac {1}{9}$

(iii) $ \frac {-2}{3}$

Additive inverse = $\frac {2}{3}$

(iv) 2

Additive inverse =-2

(v) -9/1=-9

Additive inverse =9

What is the additive identity?

- 1
- -1
- 0
- None of the above

True or False Statement

- The difference of two rational number is a rational number
- Addition of rational numbers is associative
- Addition of rational numbers is commutative
- Subtraction of rational numbers is not commutative
- The addition or subtraction of two rational number is a rational number

All the statement are true

Find the multiplicative inverse of the following.

- $ \frac {-11}{12}$
- $ \frac {-10}{9}$
- $ \frac {1}{2}$
- $\frac {-5}{2} \times \frac {-2}{5}$
- $\frac {-1}{2} \times \frac {-2}{5}$
- - 4

- $ \frac {-11}{12}$

Multiplicative inverse =>$ \frac {-12}{11}$

- $ \frac {-10}{9}$

Multiplicative inverse =$ \frac {-9}{10}$

- $ \frac {1}{2}$

Multiplicative inverse =2

- $\frac {-5}{2} \times \frac {-2}{5} =1$

Multiplicative inverse =1

- $\frac {-1}{2} \times \frac {-2}{5} = \frac {1}{5}$

Multiplicative inverse =5

- -4

Multiplicative inverse =-1/4

Which of these properties hold false for Multiplication of rational numbers?

- Associative law
- Closure law
- Commutative law
- Existence of Multiplicative identity
- None of the these

None of these

Find the below multiplication

- $ \frac {-1}{2} \times \frac {9}{10}$
- $ \frac {-25}{9} \times \frac {1}{3}$
- $\frac {7}{24} \times 10$

- $ \frac {-1}{2} \times \frac {9}{10}$

$=\frac { -1 \times 9}{2 \times 10} = \frac {-9}{20}$ - $ \frac {-25}{9} \times \frac {1}{3}$

$= \frac {-25 \times 1}{9 \times 3}= \frac {-25}{27}$ - $\frac {7}{24} \times 10$

$= \frac {7 \times 10}{24}= \frac {70}{24}$

Find the following

- (1/2)
^{-1} - (3)
^{-1} - (-6)
^{-1} - (1/-2)
^{-1}

- Multiplicative inverse of (1/2) =2
- Multiplicative inverse of (3) =1/3
- Multiplicative inverse of (-6) =-1/6
- Multiplicative inverse of (1/-2) =-2

The product of two rational number is 2 , if one of the rational number is 1/7 ,what is the value of other?

Let a be the other number, then

$a \times \frac {1}{7} =2$

Or

$a= 2 \div \frac {1}{7}$

$a=2 \times 7=14$

Fill in the blanks

(i) ____ ÷ (-3)= (-4/15)

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

(iii) The reciprocal of 1 is __________.

(iv) (1/2) ÷ (2/3) =__________.

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

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

- 4/5
- 1 and -1
- 1
- 3
- Rational Number
- Negative rational number

Write five rational numbers which are smaller than 5

0,1,2,3,4

Find five rational numbers between (1) and 2

We can write as

$1= \frac {10}{10}$

$2= \frac {20}{10}$

So five rational numbers will be

11/10, 12/10, 13/10,14/10,15/10

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Class 8 Maths Class 8 Science