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NCERT Solutions for Class 7 Maths Chapter 11 Exponents and Powers

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NCERT Solutions for Maths Class 7 Chapter 11 Exponents and Powers - FREE PDF Download

Class 7 Maths NCERT Solutions for Chapter 11 Exponents and Powers, provided by Vedantu, offer a comprehensive and straightforward explanation of key concepts. This chapter covers the fundamental rules and properties of exponents, making it crucial for understanding higher-level math topics. The solutions are designed to help students grasp the basics, such as multiplying and dividing powers, using standard form, and understanding negative exponents.

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The focus of this class 7 maths Ch 11 is on simplifying expressions involving exponents and powers, which is essential for solving complex mathematical problems efficiently. Students should pay particular attention to the laws of exponents, as these form the foundation for many algebraic operations. Access the latest CBSE Class 7 Maths Syllabus here.


Glance on Maths Chapter 11 Class 7 - Exponents and Powers

  • The chapter focuses on understanding exponents and powers to express large numbers in simplified form. 

  • Key topics include the laws of exponents such as multiplication and division of powers, power of a power, and negative exponents. 

  • Important concepts involve expressing numbers in standard form and scientific notation, and simplifying expressions involving exponents. 

  • Foundational skills are essential for algebra and higher-level math, emphasizing the mastery of rules and properties of exponents.

  • We can use exponents mainly to cut short the long number. For example, 10,000 can be written as 104

  • If the bases are equal, the exponents will follow some basic laws. 

  • am *an = am+n

  1. am / an = am-n

  2. (am)n = am+n

  3. a0 = 1

  4. -1even number  = 1

  5. -1odd number  = -1

  6.  am *bm = (ab)m

  • This article contains chapter notes, important questions, exemplar solutions, exercises and video links for Chapter 11 - Exponents and Powers, which you can download as PDFs.

  • There are three exercises (17 fully solved questions) in exponents and powers class 7.


Access Exercise Wise NCERT Solutions for Chapter 11 Maths Class 7

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Exercises Under NCERT Solutions for Class 7 Maths Chapter 11 Exponents and Powers

Exercise 11.1

  • Expressing numbers in exponential form (e.g., writing 64 as 26)

  • Identifying the base and exponent in exponential terms (e.g., recognizing 5 in 53 as the base)

  • Comparing numbers written in exponential form


Exercise 11.2

  • Simplifying exponential expressions using basic rules (like am * an = am+n)

  • Evaluating powers of numbers (e.g., finding the value of 34)

  • Using order of operations with exponents


Exercise 11.3

  • Introduction to negative exponents


Access NCERT Solutions for Class 7 Maths Chapter 11 – Exponents and Powers

Exercise 11.1

1. Find the value of:

i. 26

Ans: We have to find the value of 26. It is 2 raised to the power of 6.

26 = 2 × 2 × 2 × 2 × 2 × 2

26 = 64

Hence, the value of 26 is 64.

ii. 93

Ans: We have to find the value of 93. It is 9 raised to the power of 3.

93 = 9 × 9 × 9

93 = 729

Hence, the value of 93 is 729.

iii. 112

Ans: We have to find the value of 112. It is 11 raised to the power of 2.

112 = 11 × 11

112 = 121

Hence, the value of 112 is 121.

iv. 54

Ans: We have to find the value of 54. It is 5 raised to the power of 4.

54 = 5 × 5 × 5 × 5

54 = 625

Hence, the value of 54 is 625.


2. Express the following in exponential form:

i. × 6 × 6 × 6

Ans: We have to find the exponential form of × 6 × 6 × 6.

It is 6 multiplied four times. So, it is 6 raised to the power of 4.

× 6 × 6 × 6 = 64

Hence, × 6 × 6 × 6 can be written as 64.

ii. × t

Ans: We have to find the exponential form of × t.

It is t multiplied two times. So, it is t raised to the power of 2.

× t = t2

Hence, × t can be written as t2.

iii. × b × b × b

Ans: We have to find the exponential form of × b × b × b.

It is b multiplied four times. So, it is b raised to the power of 4.

× b × b × b = b4

Hence, × b × b × b can be written as b4.

iv. × 5 × 7 × 7 × 7

Ans: We have to find the exponential form of × 5 × 7 × 7 × 7.

It is 5 multiplied two times and 7 multiplied three times. So, it is 5 raised to the power of 2 multiplied by 7 raised to the power of 3.

× 5 × 7 × 7 × 7 = 52 × 73

Hence, × 5 × 7 × 7 × 7 can be written as 52 × 73.

v. × 2 × a × a

Ans: We have to find the exponential form of × 2 × a × a.

It is 2 multiplied two times and a multiplied two times. So, it is 2 raised to the power of 2 multiplied by a raised to the power of 2.

× 2 × a × a = 22 × a2

Hence, × 2 × a × a can be written as 22 × a2.

vi. × a × a × c × c × c × c × d

Ans: We have to find the exponential form of × a × a × c × c × c × c × d.

It is a multiplied three times and c multiplied four times and d multiplied once.

× a × a × c × c × c × c × d = a3 × c4 × d

Hence, × a × a × c × c × c × c × d can be written as a3 × c4 × d.


3. Express each of the following numbers using exponential notation:

i. 512

Ans: We can write 512 as following:

512 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2

512 = 29

Hence, the value of 512 in exponential form is 29.

ii. 343

Ans: We can write 343 as following:

343 = 7 × 7 × 7

343 = 73

Hence, the value of 343 in exponential form is 73.

iii. 729

Ans: We can write 729 as following:

729 = 3 × 3 × 3 × 3 × 3 × 3

729 = 36

Hence, the value of 729 in exponential form is 36.

iv. 3125

Ans: We can write 3125 as following:

3125 = 5 × 5 × 5 × 5 × 5

3125 = 55

Hence, the value of 3125 in exponential form is 55.


4. Identify the greater number, wherever possible, in each of the following:

i. 43 and 34

Ans: We will first write the values of each of the exponential forms.

43 = 4 × 4 × 4 = 64

34 = 3 × 3 × 3 × 3 = 81

Since 81 > 64, we can say that 34 > 43.

Hence, the greater number is 34.

ii. 53 or 35

Ans: We will first write the values of each of the exponential forms.

53 = 5 × 5 × 5 = 125

35 = 3 × 3 × 3 × 3 × 3 = 243

Since 125 < 243, we can say that 35 > 53.

Hence, the greater number is 35.

iii. 28 or 82

Ans: We will first write the values of each of the exponential forms.

28 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 256

82 = 8 × 8 = 64

Since 256  64, we can say that 28 82.

Hence, the greater number is 28.

iv. 1002 or 2100

Ans: We will first write the values of each of the exponential forms.

1002 = 100 × 100 = 10000

2100 = 2 × 2 × 2 × ...14 times × 2 × ...

2100 = 16384 × 2 × 2×...

Since 10000  < 16384 × 2 × ..., we can say that 2100 >1002.

Hence, the greater number is 2100.

v. 210 or 102

Ans: We will first write the values of each of the exponential forms.

210 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 1024

102 = 10 × 10 = 100

Since 1024  100, we can say that 210 102.

Hence, the greater number is 210.


5. Express each of the following as product of their prime factors:

i. 648

Ans: We can write 648 as following:

648 = 2 × 2 × 2 × 3 × 3 × 3 × 3

648 = 23 × 34

Hence, the value of 648 in exponential form is 23 × 34.

ii. 405

Ans: We can write 405 as following:

405 = 3 × 3 × 3 × 3 × 5

405 = 34 × 5

Hence, the value of 405 in exponential form is × 34.

iii. 540

Ans: We can write 540 as following:

540 = 2 × 2 × 3 × 3 × 3 × 5

540 = 22 × 33 × 5

Hence, the value of 540 in exponential form is 22 × 33 × 5.

iv. 3600

Ans: We can write 3600 as following:

3600 = 2 × 2 × 2 × 2 × 3 × 3 × 5 × 5

3600 = 24 × 32 × 52

Hence, the value of 3600 in exponential form is 24 × 32 × 52.


6. Simplify:

i. × 103

Ans: We have to simplify × 103.

× 103 = 2 × 10 × 10 × 10

× 103 = 2000

Hence, the value of × 103 is 2000.

ii. 72 × 22

Ans: We have to simplify 72 × 22.

72 × 22 = 7 × 7 × 2 × 2

72 × 22 = 196

Hence, the value of 72 × 22 is 196.

iii. 23 × 5

Ans: We have to simplify 23 × 5.

23 × 5 = 2 × 2 × 2 × 5

23 × 5 = 40

Hence, the value of 23 × 5 is 40.

iv. × 44

Ans: We have to simplify × 44.

× 44 = 3 × 4 × 4 × 4 × 4

× 44 = 768

Hence, the value of × 44 is 768.

v. × 102

Ans: We have to simplify × 102.

× 102 = 0 × 10 × 10

× 102 = 0

Hence, the value of × 102 is 0.

vi. 52 × 33

Ans: We have to simplify 52 × 33.

52 × 33 = 5 × 5 × 3 × 3 × 3

52 × 33 = 675

Hence, the value of 52 × 33 is 675.

vii. 24 × 32

Ans: We have to simplify 24 × 32.

24 × 32 = 2 × 2 × 2 × 2 × 3 × 3

24 × 32 = 144

Hence, the value of 24 × 32 is 144.

viii. 32 × 104

Ans: We have to simplify 32 × 104.

32 × 104 = 3 × 3 × 10 × 10 × 10 × 10

32 × 104 = 90000

Hence, the value of 32 × 104 is 90000.


7. Simplify:

i. (-4)3

Ans: We have to simplify (-4)3.

(-4)3 = (-4) × (-4) × (-4)

(-4)3 = -64

Hence, the value of (-4)3 is -64.

ii. (-3) × (-2)3

Ans: We have to simplify (-3) × (-2)3.

(-3) × (-2)3 = (-3) × (-2) × (-2) × (-2)

(-3) × (-2)3 = 24

Hence, the value of (-3) × (-2)3 is 24.

iii. (-3)2 × (-5)2

Ans: We have to simplify (-3)2 × (-5)2.

(-3)2 × (-5)2 = (-3) × (-3) × (-5) × (-5)

(-3)2 × (-5)2 = 225

Hence, the value of (-3)2 × (-5)2 is 225.

iv. (-2)3 × (-10)3

Ans: We have to simplify (-2)3 × (-10)3.

(-2)3 × (-10)3 = (-2) × (-2) × (-2) × (-10) × (-10) × (-10)

(-2)3 × (-10)3 = 8000

Hence, the value of (-2)3 × (-10)3 is 8000.


8. Compare the following numbers:

i. 2.7 × 1012; 1.5 × 108

Ans: We have to compare 2.7 × 1012 and 1.5 × 108.

We will get the solution by simply comparing the exponents of base 10.

1012 108

Hence, we can say that 2.7 × 1012 1.5 × 108.

ii. × 1014; 3 × 1017

Ans: We have to compare × 1014 and × 1017.

We will get the solution by simply comparing the exponents of base 10.

1017 1014

Hence, we can say that × 1017 4 × 1014.


Exercise 11.2

1. Using laws of exponents, simplify and write the answer in exponential form:

i. 32 × 34 × 38

Ans: We have to simplify 32 × 34 × 38.

We know the law of exponents am × an = am+n.

32 × 34 × 38 = 32+4+8

32 × 34 × 38 = 314

Hence, we can write 32 × 34 × 38 as 314.

ii. 615 ÷ 610

Ans: We have to simplify 615 ÷ 610.

We know the law of exponents am ÷ an = am-n.

615 ÷ 610 = 615-10

615 ÷ 610 = 65

Hence, we can write 615 ÷ 610 as 65.

iii. a3 × a2

Ans: We have to simplify a3 × a2.

We know the law of exponents am × an = am+n.

a3 × a2 = a3+2

a3 × a2 = a5

Hence, we can write a3 × a2 as a5.

iv. 7x × 72

Ans: We have to simplify 7x × 72.

We know the law of exponents am × an = am+n.

7x × 72 = 7x+2

7x × 72 = 7x+2

Hence, we can write 7x × 72 as 7x+2.

v. (52)3 ÷ 53

Ans: We have to simplify (52)3 ÷ 53.

We know the law of exponents (am)n = a× n.

(52)3 ÷ 53 = 5× 3 ÷ 53 = 56 ÷ 53

We know the law of exponents am ÷ an = am-n.

56 ÷ 53 = 56-3

56 ÷ 53 = 53

Hence, we can write (52)3 ÷ 53 as 53.

vi. 25 × 55

Ans: We have to simplify 25 × 55.

We know the law of exponents am × bm = (× b)m.

25 × 55 = (× 5)5

25 × 55 = 105

Hence, we can write 25 × 55 as 105.

vii. a4 × b4

Ans: We have to simplify a4 × b4.

We know the law of exponents am × bm = (× b)m.

a4 × b4 = (× b)4

Hence, we can write a4 × b4 as (× b)4.

viii. (34)3

Ans: We have to simplify (34)3.

We know the law of exponents (am)n = a× n.

(34)3 = 3× 3 = 312

Hence, we can write (34)3 as 312.

ix. (220 ÷ 215) × 23

Ans: We have to simplify (220 ÷ 215) × 23.

We know the law of exponents am ÷ an = am-n.

(220 ÷ 215) × 23 = (220-15) × 23 = 25 × 23

We know the law of exponents am × bm = (× b)m.

25 × 23 = 25+3 = 28

Hence, we can write (220 ÷ 215) × 23 as 28.

x. 8t ÷ 82

Ans: We have to simplify 8t ÷ 82.

We know the law of exponents am ÷ an = am-n.

8t ÷ 82 = 8t-2

Hence, we can write 8t ÷ 82 as 8t-2.


2. Simplify and express each of the following in exponential form:

i. 23 × 34 × 4× 32

Ans: We have to simplify 23 × 34 × 4× 32.

23 × 34 × 4× 32 = 23 × 34 × 22× 25  

We know the law of exponents am × an = am+n.

23 × 34 × 22× 25 = 23+2 × 34× 25 = 25 × 34× 25 = 343

We know the law of exponents am ÷ an = am-n.

343 = 34-1 = 33

Hence, we can write 23 × 34 × 4× 32 as 33.

ii. [(52)3 × 54] ÷ 57

Ans: We have to simplify [(52)3 × 54] ÷ 57.

We know the law of exponents (am)n = a× n.

[(52)3 × 54] ÷ 57 = [5× 3 × 54] ÷ 57 = [56 × 54] ÷ 57

We know the law of exponents am × an = am+n.

[56 × 54] ÷ 57 = 56+4 ÷ 57 = 510 ÷ 57

We know the law of exponents am ÷ an = am-n.

510 ÷ 57 = 510-7 = 53

Hence, we can write [(52)3 × 54] ÷ 57 as 53.

iii. 254 ÷ 53

Ans: We have to simplify 254 ÷ 53.

254 ÷ 53 = (52)4 ÷ 53

We know the law of exponents (am)n = a× n.

(52)4 ÷ 53 = 5× 4 ÷ 53 = 58 ÷ 53

We know the law of exponents am ÷ an = am-n.

58 ÷ 53 = 58-3 = 55

Hence, we can write 254 ÷ 53 as 55.

iv. × 72 × 11821 × 113

Ans: We have to simplify × 72 × 11821 × 113.

× 72 × 11821 × 113 = × 72 × 118× 7 × 113 = 33 × 727 × 118113

We know the law of exponents am ÷ an = am-n.

33 × 727 × 118113 = 31-1 × 72-1 × 118-3 = 7 × 115

Hence, we can write × 72 × 11821 × 113 as × 115.

v. 3734 × 33

Ans: We have to simplify 3734 × 33.

We know the law of exponents am × an = am+n.

3734 × 33 = 3734+3 = 3737

We know the law of exponents am ÷ an = am-n.

3737 = 37-7 = 30 = 1

Hence, we can write 3734 × 33 as 1.

vi. 20+30+40

Ans: We have to simplify 20+30+40.

We know the value of a0=1.

20+30+40 = 1+1+1 = 3

Hence, we can write 20+30+40 as 3.

vii. 20 × 30 × 40

Ans: We have to simplify 20×30×40.

We know the value of a0=1.

20 × 30 × 40 = 1 × 1 × 1 = 1

Hence, we can write 20×30×40 as 1.

viii. (30+20) × 50

Ans: We have to simplify (30+20) × 50.

We know the value of a0=1.

(30+20) × 50 = (1+1) × 1 = 2 × 1 = 2

Hence, we can write (30+20) × 50 as 2.

ix. 28 × a543 × a3

Ans: We have to simplify 28 × a543 × a3.

28 × a543 × a3 = 28 × a5(22)3 × a3

We know the law of exponents (am)n = a× n.

28 × a5(22)3 × a3 = 28 × a52× 3 × a3 = 28 × a526 × a3 = 2826 × a5a3

We know the law of exponents am ÷ an = am-n.

2826 × a5a3 = 28-6 × a5-3 = 22 × a2

We know the law of exponents am × bm = (ab)m.

22 × a2 = (2a)2

Hence, we can write 28 × a543 × a3 as (2a)2.

x. (a5a3) × a8

Ans: We have to simplify (a5a3) × a8.

We know the law of exponents am ÷ an = am-n.

(a5a3) × a8 = a5-3 × a8 = a2 × a8

We know the law of exponents am × an = am+n.

a2 × a8 = a2+8 = a10

Hence, we can write (a5a3) × a8 as a10.

xi. 45 × a8b345 × a5b2

Ans: We have to simplify 45 × a8b345 × a5b2.

We know the law of exponents am ÷ an = am-n.

45 × a8b345 × a5b2 = 45-5 × a8-5 × b3-2 = 40a3b1 = a3b

Hence, we can write 45 × a8b345 × a5b2 as a3b.

xii. (23 × 2)2

Ans: We have to simplify (23 × 2)2.

We know the law of exponents am × an = am+n.

(23 × 2)2 = (23+1)2 = (24)2

We know the law of exponents (am)n = a× n.

(24)2 = 2× 2 = 28

Hence, we can write (23 × 2)2 as 28.


3. Say true or false and justify your answer:

i. 10 × 1011 = 10011

Ans: The given statement is false.

Explanation:

LHS: It is given 10 × 1011.

We know the law of exponents am × an = am+n.

10 × 1011 = 101+11 = 1012


RHS: It is given 10011.

We have obtained that LHS  RHS

Hence, the statement is false.

ii. 23 52

Ans: The given statement is false.

Explanation:

LHS: It is given 23.

23 = 2 × 2 × 2 = 8


RHS: It is given 52.

52 = 5 × 5 = 25

We have obtained that LHS  < RHS

Hence, the statement is false.

iii. 23 × 32 = 65

Ans: The given statement is false.

Explanation:

LHS: It is given 23 × 32.

23 × 32 = 2 × 2 × 2 × 3 × 3 = 72


RHS: It is given 65.

65 = 6 × 6 × 6 × 6 × 6 = 7776

We have obtained that LHS  RHS

Hence, the statement is false.

iv. 30 = (1000)0

Ans: The given statement is true.

Explanation:

LHS: It is given 30.

30 = 1


RHS: It is given 10000.

10000 = 1

We have obtained that LHS = RHS

Hence, the statement is true.


4. Express each of the following as a product of prime factors only in exponential form:

i. 108 × 192

Ans: We have to express 108 × 192 in exponential form.

108 = 2 × 2 × 3 × 3 × 3 = 22 × 33

192 = 2 × 2 × 2 × 2 × 2 × 2 × 3 = 26 × 31

108 × 192 = (22 × 33) × (26 × 31)

We know the law of exponents am × an = am+n.

108 × 192 = 22+6 × 33+1

108 × 192 = 28 × 34

Hence, we can write 108 × 192 as 28 × 34.

ii. 270

Ans: We have to express 270 in exponential form.

270 = 2 × 3 × 3 × 3 × 5 = 21 × 33 × 5 = 2 × 33 × 5

Hence, we can write 270 as × 33 × 5.

iii. 729 × 64

Ans: We have to express 729 × 64 in exponential form.

729 = 3 × 3 × 3 × 3 × 3 × 3 = 36

64 = 2 × 2 × 2 × 2 × 2 × 2 = 26

729 × 64 = 36 × 26


Hence, we can write 729 × 64 as 36 × 26.

iv. 768

Ans: We have to express 768 in exponential form.

270 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 = 28 × 31 = 28 × 3

Hence, we can write 768 as 28 × 3.


5. Simplify:

i. (25)2 × 7383 × 7

Ans: We have to simplify (25)2 × 7383 × 7

(25)2 × 7383 × 7 = (25)2 × 73(23)3 × 7

We know the law of exponents (am)n = a× n.

(25)2 × 73(23)3 × 7 = 2× 2 × 732× 3 × 7 = 210 × 7329 × 7

We know the law of exponents am ÷ an = am-n.

210 × 7329 × 7 = 210-9 × 73-1 = 21 × 72 =98

Therefore, the value of (25)2 × 7383 × 7 is 98.

ii. 25 × 52 × t8103 × t4

Ans: We have to simplify 25 × 52 × t8103 × t4.

25 × 52 × t8103 × t4=52 × 52 × t8(5×2)3 × t4

We know the law of exponents am × bm = (× b)m.

52 × 52 × t8(× 2)3 × t4=52 × 52 × t853 × 23 × t4

We know the law of exponents am × an = am+n.

52 × 52 × t853 × 23 × t4 = 52+2 × t853 × 23 × t4=54 × t853 × 23 × t4

We know the law of exponents am ÷ an = am-n.

54 × t853 × 23 × t4 = 54-3 × t8-423 = 51 × t423 = 5t48

Therefore, the value of 25 × 52 × t8103 × t4 is 5t48.

iii. 35 × 105 × 2557 × 65

Ans: We have to simplify 35 × 105 × 2557 × 65.

35 × 105 × 2557 × 65 = 35 × (× 2)5 × 5257 × (× 2)5

We know the law of exponents am × bm = (× b)m.

35 × (× 2)5 × 5257 × (× 2)5 = 35 × 55 × 25 × 5257 × 35 × 25

We know the law of exponents am × an = am+n.

35 × 55 × 25 × 5257 × 35 × 25 = 35 × 55+2 × 2557 × 35 × 25 = 35 × 57 × 2557 × 35 × 25

We know the law of exponents am ÷ an = am-n.

35 × 57 × 2557 × 35 × 25 = 35-5 × 57-7 × 25-5

35 × 57 × 2557 × 35 × 25 = 30 × 50 × 20

35 × 57 × 2557 × 35 × 25 = 1 × 1 × 1 = 1

Therefore, the value of 35 × 105 × 2557 × 65 is 1.

.

Exercise 11.3

1. Write the following numbers in the expanded form:

a. 279404

Ans: We have to expand 279404.

279404 = 200000+70000+9000+400+4

279404 = 2 × 100000+7 × 10000 + 9 × 1000 + 4 × 100 + 4 × 1

279404 = 2 × 105+7 × 104 + 9 × 103 + 4 × 102 + 4 × 100

Hence, the expanded form of 279404 is × 105+7 × 104 + 9 × 103 + 4 × 102 + 4 × 100.

b. 3006194

Ans: We have to expand 3006194.

3006194 = 3000000 + 6000 + 100 + 90 + 4

3006194 = 3 × 1000000 + 6 × 1000 + 1 × 100 + 9 × 10 + 4 × 1

3006194 = 3 × 106 + 6 × 103 + 1 × 102+ 9 × 101 + 4 × 100

Hence, the expanded form of 3006194 is × 106 + 6 × 103 + 1 × 102+ 9 × 101 + 4 × 100.

c. 2806196

Ans: We have to expand 2806196.

2806196 = 2000000 + 800000 + 6000 + 100 + 90 + 6

2806196 = 2 × 1000000 + 8 × 100000 + 6 × 1000 + 1 × 100 + 9 × 10 + 6 × 1

2806196 = 2 × 106 + 8 × 105+ 6 × 103 + 1 × 102+ 9 × 101 + 6 × 100

Hence, the expanded form of 2806196 is × 106 + 8 × 105+ 6 × 103 + 1 × 102+ 9 × 101 + 6 × 100.

d. 120719

Ans: We have to expand 120719.

120719 = 100000 + 20000 + 700 +10 + 9

120719 = 1 × 100000 + 2 × 10000 + 7 × 100 +1 × 10 + 9 × 1

120717 = 1 × 105 + 2 × 104 + 7 × 102 +1 × 101 + 7 × 100

Hence, the expanded form of 120719 is × 105 + 2 × 104 + 7 × 102 +1 × 101 + 7 × 100.

e. 20068

Ans: We have to expand 20068.

20068 = 20000 +60 + 8

20068 = 2 × 10000 +6 × 10 + 8 × 1

20068 = 2 × 104 +6 × 101 + 8 × 100

Hence, the expanded form of 20068 is × 104 +6 × 101 + 8 × 100.


2. Find the number from each of the following expanded form:

a. × 104 + 6 × 103 + 0 × 102 + 4 × 101 + 5 × 100

Ans: We are given × 104 + 6 × 103 + 0 × 102 + 4 × 101 + 5 × 100

We will now simplify it.

= 8 × 10000 + 6 × 1000 + 0 × 100 + 4 × 10 + 5 × 1

= 80000 + 6000 + 0 + 40 + 5

= 86045

Hence, the required number is 86045.

b. × 105 + 5 × 103 + 3 × 102 + 2 × 100

Ans: We are given × 105 + 5 × 103 + 3 × 102 + 2 × 100

We will now simplify it.

= 4 × 100000 + 5 × 1000 + 3 × 100 + 0 × 10 + 2 × 1

= 400000 + 5000 + 300 + 0 + 2

= 405302

Hence, the required number is 405302.

c. × 104 + 7 × 102 +  5 × 100

Ans: We are given × 104 + 7 × 102 + 5 × 100

We will now simplify it.

= 3 × 10000 + 7 × 100 + 5 × 1

= 30000 + 700 + 5

= 30705

Hence, the required number is 30705.

d. × 105 + 2 × 102 +  3 × 101

Ans: We are given × 105 + 2 × 102 + 3 × 101

We will now simplify it.

= 9 × 100000 + 2 × 100 + 3 × 10

= 900000 + 200 + 30

= 900230

Hence, the required number is 900230.


3. Express the following numbers in standard form:

i. 5,00,00,000

Ans: We have to write the given number in standard form.

5,00,00,000 = 5 × 1,00,00,000 = 5 × 107

Hence, the standard form is × 107.

ii. 70,00,000

Ans: We have to write the given number in standard form.

70,00,000 = 7 × 10,00,000 = 7 × 106

Hence, the standard form is × 106.

iii. 3,18,65,00,000

Ans: We have to write the given number in standard form.

3,18,65,00,000 = 31865 × 1,00,000 = 3.1865 × 104 × 105 = 3.1865 × 109

Hence, the standard form is 3.1865 × 109.

iv. 3,90,878

Ans: We have to write the given number in standard form.

3,90,878 = 3.90878 × 1,00,000 = 3.90878 × 105

Hence, the standard form is 3.90878 × 105.

v. 39087.8

Ans: We have to write the given number in standard form.

39087.8 = 3.90878 × 10,000 = 3.90878 × 104

Hence, the standard form is 3.90878 × 104.

vi. 3908.78

Ans: We have to write the given number in standard form.

3908.78 = 3.90878 × 1,000 = 3.90878 × 103

Hence, the standard form is 3.90878 × 103.


4. Express the number appearing in the following statements in standard form:

a. The distance between Earth and Moon is 384,000,000 m.

Ans: We have to write 384,000,000in standard form.

384,000,000 = 3.84 × 100,000,000 = 3.84 × 108

Hence, the required standard form is 3.84 × 108 m.

b. Speed of light in vacuum is 300,000,000 m/s.

Ans: We have to write 300,000,000in standard form.

300,000,000 = 3 × 100,000,000 = 3 × 108

Hence, the required standard form is × 108 m/s.

c. Diameter of Earth is 1,27,56,000 m.

Ans: We have to write 1,27,56,000in standard form.

1,27,56,000 = 1.2756 × 1,00,00,000 = 1.2756 × 107

Hence, the required standard form is 1.2756 × 107 m.

d. Diameter of Sun is 1,400,000,000 m.

Ans: We have to write 1,400,000,000 in standard form.

1,400,000,000 = 1.4 × 1,000,000,000 = 1.4 × 109

Hence, the required standard form is 1.4 × 109 m.

e. In a galaxy there are on average 100,000,000,000 stars.

Ans: We have to write 100,000,000,000 in standard form.

100,000,000,000 = 1 × 100,000,000,000 = 1 × 1011

Hence, the required standard form is × 1011 stars.

f. The universe is estimated to be about 12,000,000,000 years old.

Ans: We have to write 12,000,000,000 in standard form.

12,000,000,000 = 1.2 × 10,000,000,000 = 1.2 × 1010

Hence, the required standard form is 1.2 × 1010 years.

g. The distance of the Sun from the centre of the Milky Way  galaxy is estimated to be 300,000,000,000,000,000,000 m.

Ans: We have to write 300,000,000,000,000,000,000 in standard form.

300,000,000,000,000,000,000 = 3 × 1020

Hence, the required standard form is × 1020 m.

h. 60,230,000,000,000,000,000,000 molecules are contained in a drop of water weighing 1.8 gm.

Ans: We have to write 60,230,000,000,000,000,000,000 in standard form.

60,230,000,000,000,000,000,000 = 6.023 × 1022

Hence, the required standard form is 6.023 × 1022 molecules.

i. The Earth has 1,353,000,000 cubic km of water.

Ans: We have to write 1,353,000,000 in standard form.

1,353,000,000 = 1.353 × 1,000,000,000 = 1.353 × 109

Hence, the required standard form is 1.353 × 109 cubic km.

j. The population of India was about 1,027,000,000 in March, 2001.

Ans: We have to write 1,027,000,000 in standard form.

1,027,000,000 = 1.027 × 1,000,000,000 = 1.027 × 109

Hence, the required standard form is 1.027 × 109.


Class 7 Maths Chapter 11: Exercises Breakdown

Exercise

Number of Questions

Exercise 11.1

8 Questions & Solutions

Exercise 11.2

5 Questions & Solutions

Exercise 11.3

4 Questions & Solutions



Conclusion

In conclusion, Exponents and Powers Class 7 equips you with a foundational understanding of expressing large numbers compactly and efficiently. Learn how to write repeated multiplication using exponents, explore properties of exponents for simplifying calculations, and gain an introduction to working with powers. With this knowledge, you can solve problems involving large numbers and lay the groundwork for more complex mathematical concepts in higher grades. In previous years exams around 1-2 questions appeared from ​​Class 7 Maths Ch 11.


Other Study Material for CBSE Class 7 Maths Chapter 11

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Important Links for Chapter 11 Exponents and Powers

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Class 7 Exponents and Powers Important Questions

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Class 7 Exponents and Powers Revision Notes

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Class 7 Exponents and Powers Important Formulas

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Class 7 Exponents and Powers NCERT Exemplar Solution



Chapter-Specific NCERT Solutions for Class 7 Maths

Given below are the chapter-wise NCERT Solutions for Class 7 Maths. Go through these chapter-wise solutions to be thoroughly familiar with the concepts.




Access these essential links for NCERT Class 7 Maths, offering comprehensive solutions, study guides, and additional resources to help students master language concepts and excel in their exams.


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FAQs on NCERT Solutions for Class 7 Maths Chapter 11 Exponents and Powers

1. What do you understand by ‘Exponents and Powers’?

When a number is multiplied to itself for a certain number of times, then the number is said to be raised to a power. For example, in the following expression, 26, the integer 2 is raised to a power of 6. To get the resultant, you have to multiply 2 to itself 6 times. Here, the integer 2 is termed as the base and the integer 6 is termed as the exponent or power of 2. The exponent is the number of times for which the base is multiplied to itself.


The concept of ‘Exponents and Powers’ is introduced in the school level academics, and students are suggested to practice the sums of this chapter as they will come across various real-life applications of this concept.

2. Can I find the NCERT Solutions for Class 7 Maths Chapter 13 online?

Yes, you can find the NCERT Solutions for Class 7 Maths Chapter 13 online, on Vedantu. These solutions are verified recommended by experts. All the sums of this chapter are solved in a step by step manner in the PDF of these NCERT solutions. The concept of Exponents and Powers is very interesting and when you go through these solved exercises, you will be able to develop a deeper understanding of the same.

3. Are the NCERT Solutions for Class 7 Maths Chapter 13 reliable study resources?

Yes, the NCERT Solutions for Class 7 Maths Chapter 13 are very reliable study resources. The in-house team of subject matter experts at Vedantu has prepared these solutions to facilitate an easy learning process for all students. Every sum is solved as per the CBSE guidelines for Class 9, so students can rely on these NCERT solutions for their exam preparation. They can solve the exercises of Exponents and Powers, on their own and compare their answers with these step-wise solutions. In this way, it will become easier for students to identify their silly mistakes and rectify them. These NCERT solutions are very reliable study resources for self-study and revision purposes before the examination.

4. Can I download the NCERT Solutions for Class 7 Maths Chapter 13 ‘Exponents and Powers’ for free?

Yes, you can download the NCERT Solutions for Class 7 Maths Chapter 13 ‘Exponents and Powers’ for absolutely free of cost from Vedantu. These NCERT solutions are available in the PDF format on our mobile application as well. Thereby, making the best-rated study resources for this Math chapter available for all students. All you need to access these NCERT solutions is internet connectivity and a digital screen. Yes, you can download these NCERT solutions even on your smartphones or tablets. So download and refer to the NCERT Solutions for Class 7 Maths Chapter 13 ‘Exponents and Powers’ right away, for an easy learning experience.

5. Why are exponents necessary?

Exponents allow you to write large numbers in a readable and concise manner. The principles and regulations constructed around exponents are included in the NCERT Solutions for Class 7 Mathematics Chapter 13 Exponents and Powers. In Mathematics, science, and geography, large numbers are frequently used. It is tough not only to read them but also to perform Mathematics with them. Exponents and powers are used to make numbers easier to read and manipulate. As a result, these NCERT solutions for Class 7 Maths Chapter 13 teach students to write long numbers in short form notation.

6. Why should I practise Chapter 13 of NCERT Solutions for Class 7 Maths Exponents and Powers?

The NCERT Solutions for Class 7 Maths Exponents and Powers Chapter 13 has been carefully crafted by NCERT's top academics, making it a valuable learning resource. They made certain that the principles were conveyed in simple terms and that all of the important topics were addressed in depth. The CBSE board also strongly encourages pupils to study from the NCERT books, making it a significant practice resource for them.

7. How can CBSE students properly use NCERT Solutions for Chapter 13 of Class 7 Maths?

Students must take it carefully throughout the chapter, moving ahead only after they have a firm grasp of the concepts in each section. When exploring new concepts, poor comprehension of earlier concepts will lead to misunderstanding. They must also practice all of the solved instances to reinforce their newly acquired knowledge. They would be able to properly use the NCERT Solutions Class 7 Maths Chapter 13 in this manner. Refer to Vedantu for the NCERT Solution of this chapter.

8. How many questions are there in Chapter 13 Exponents and Powers of the NCERT Solutions for Class 7 Maths?

There are 17 questions in Class 7 Maths Chapter 13 Exponents and Powers, with several subparts. 12 of them are quite simple because they require exponential representation, and 5 of them are a little more complicated due to the computations involved. All of the solved problems are available in pdf format on Vedantu's website. Solve those problems first, then cross-check with the answers you've already figured out.

9. What are the key laws in Chapter 13 of NCERT Solutions for Class 7 Maths?

The law of exponents is discussed in NCERT Solutions Class 7 Maths Chapter 13 and certain key laws are explained. Here are a few examples: The addition of exponents' powers results from multiplication, while the subtraction of exponents' powers results from division. Furthermore, the strength of power causes them to multiply. These are crucial hints that pupils will require when answering questions.

10. What are the basic rules of exponents covered in exponents and powers class 7 pdf?

The basic rules of exponents include multiplying powers with the same base, dividing powers with the same base, and raising a power to another power. These rules are fundamental for simplifying complex expressions. Understanding these principles is essential for solving problems efficiently and accurately in various mathematical contexts.

11. How do exponents help in representing large numbers?

In exponents and powers class 7 pdf allow large numbers to be written in a compact form using powers, which simplifies both writing and calculations. For example, instead of writing a million, we use an exponent to express it succinctly. This method is particularly useful in scientific notation, making it easier to handle and communicate very large or very small values.

12. What is the significance of negative exponents in class 7 maths Chapter 11 pdf solutions?

In class 7 maths Chapter 11 pdf solutions negative exponents represent the reciprocal of the base raised to the corresponding positive exponent. This means that an expression with a negative exponent is equivalent to one divided by that base raised to the positive exponent. Understanding negative exponents is crucial for simplifying expressions and solving equations that involve powers and roots.