MEDIUM
8th Andhra Pradesh Board
IMPORTANT
Earn 100

Complete the following table.

Numbers Commutative with respect to
Addition Subtraction Multiplication Division
Natural numbers Yes No Yes  
Whole numbers       No
Integers        
Rational Numbers       No

Important Questions on Rational Numbers

MEDIUM
8th Andhra Pradesh Board
IMPORTANT

Complete the table with necessary illustrations and remarks for whole numbers.

Operation Examples with whole numbers Remark
Addition

Is 2+(3+0)=(2+3)+0?

2+(3+0)=2+3=5

(2+3)+0=5+0=5

2+(3+0)=(2+3)+0

a+(b+c)=(a+b)+c

for any three whole numbers a, b, c

 
Subtraction

(2-3)-2=? 2-(3-2)=?  

Is (2-3)-2=2-(3-2)?

Subtraction is not associative
Multiplication   Multiplication is associative
Division

Is 2÷(3÷5)=(2÷3)÷5?

2÷3÷5=2÷35=2×53=103

2÷3÷5=23÷5=23×15=215

2÷3÷52÷3÷5

Division is not associative
MEDIUM
8th Andhra Pradesh Board
IMPORTANT

Complete the table with necessary illustrations and remarks for integers.

Operation Integers with example Remark
Addition

Is 2+[(-3)+5)]=[(2+(-3)]+5?

2+[(-3)+5]=2+[-3+5]=2+2=4

 [2+(-3)]+5=[2-3]+5=-1+5=4

For any three integers a, b, c

a+(b+c)=(a+b)+c

 
Subtraction

Is 6-(9-5)=(6-9)-5?

 
Multiplication Is 2×[7×(-3)]=(2×7)×(-3)?  
Division

10÷ [2÷(-5)]=[10÷2]÷(-5)?

10÷2÷-5=10÷2-5=10×-52=-25

Now, 10÷2÷-5=102÷-5=5÷-5=5-5=-1

Thus, 10÷ [2÷(-5)][10÷2]÷(-5)

 
MEDIUM
8th Andhra Pradesh Board
IMPORTANT

Complete the following table.

Numbers Associative under
Addition Subtraction Multiplication Division
Natural numbers Yes      
Whole numbers       No
Integers   Yes    
Rational Numbers     Yes  
MEDIUM
8th Andhra Pradesh Board
IMPORTANT

Fill in the following blanks.

3×_____=3 and _____×3=3

-2×_____=-2 and _____×-2=-2

78×_____=78 and _____×78=78

What observations have you made in the above multiplications?

EASY
8th Andhra Pradesh Board
IMPORTANT
What is the multiplicative identity for integers and whole numbers?
EASY
8th Andhra Pradesh Board
IMPORTANT

Use appropriate property:

1×_____=1

EASY
8th Andhra Pradesh Board
IMPORTANT

Find the multiplicative inverse.

-1×_____=1

EASY
8th Andhra Pradesh Board
IMPORTANT
If a property holds good with respect to addition for rational numbers, whether it holds good for integers? And for whole numbers? Which one holds good and which doesn't hold good?