Class 8 Exam  >  Class 8 Notes  >  Mental Mathematics for Class 8  >  Mental Maths Questions and Answers: Square and Square Roots

Mental Maths Questions and Answers: Square and Square Roots | Mental Mathematics for Class 8 PDF Download

Download, print and study this document offline
Please wait while the PDF view is loading
 Page 1


  
 
 
Square and Square Roots 
Points to Remember 
? A Natural number x is a perfect square if there exists a natural number y such 
that x=y
2
. 
? A number ending in 2, 3, 7 or 8 is never a perfect square. 
? The number of zeros in the end of a perfect square is never odd. 
? Square of even numbers are always even. 
? Square of odd numbers are always odd. 
? Sum of first ?? natural numbers= 
?? (?? +?? )
?? 
? Sum of first ?? natural even numbers=?? (?? + ?? ) 
? Sum of first ?? natural odd numbers=?? ?? 
? The square of a natural number other than 1 is either a multiple of 4 or exceeds 
a multiple of 4 by 1. 
? The square of a natural number other than 1 is either a multiple of 3 or exceeds 
a multiple of 3 by 1. 
? For any number ?? greater than 1, (?? ?? , ?? ?? - ?? , ?? ?? + ?? )is a Pythagorean triplet. 
 
QUESTIONS 
1. How many perfect squares lie between 100 and 1000? 
2. Write the smallest four digit perfect square number. 
3. Find the value of x, if (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
4. Simplify:v ???? × ?? + ???? × ?? 
5. Simplify:
v
(?? . ???? ) + v ?? . ???????? 
6. Simplify:
v
?????? +
v
?? + v ???? 
7. Simplify:v???????? × v
????????
?? .????
 
8. Find the value of (?????? )
?? - (?????? )
?? 
9. Simplify: ?? ?? - ?? ?? + ?? ?? - ?? ?? + ?? ?? 
Page 2


  
 
 
Square and Square Roots 
Points to Remember 
? A Natural number x is a perfect square if there exists a natural number y such 
that x=y
2
. 
? A number ending in 2, 3, 7 or 8 is never a perfect square. 
? The number of zeros in the end of a perfect square is never odd. 
? Square of even numbers are always even. 
? Square of odd numbers are always odd. 
? Sum of first ?? natural numbers= 
?? (?? +?? )
?? 
? Sum of first ?? natural even numbers=?? (?? + ?? ) 
? Sum of first ?? natural odd numbers=?? ?? 
? The square of a natural number other than 1 is either a multiple of 4 or exceeds 
a multiple of 4 by 1. 
? The square of a natural number other than 1 is either a multiple of 3 or exceeds 
a multiple of 3 by 1. 
? For any number ?? greater than 1, (?? ?? , ?? ?? - ?? , ?? ?? + ?? )is a Pythagorean triplet. 
 
QUESTIONS 
1. How many perfect squares lie between 100 and 1000? 
2. Write the smallest four digit perfect square number. 
3. Find the value of x, if (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
4. Simplify:v ???? × ?? + ???? × ?? 
5. Simplify:
v
(?? . ???? ) + v ?? . ???????? 
6. Simplify:
v
?????? +
v
?? + v ???? 
7. Simplify:v???????? × v
????????
?? .????
 
8. Find the value of (?????? )
?? - (?????? )
?? 
9. Simplify: ?? ?? - ?? ?? + ?? ?? - ?? ?? + ?? ?? 
  
 
10. Simplify:(v?????? ÷ ?? )
?? 
11. Simplify:v?????? + v ?? . ???? 
12. Simplify:v
?? ???? .?? 
13. How many 2’s are there in the prime factorization of 4000? 
14. Find the least number that should be added to 221 to get a perfect square. 
15. If area of a square field is 1764 sq. m. Find its perimeter. 
16. How many numbers lie between (???? )
?? and (???? )
?? ? 
17. Find the value of(???? + ?? + ?? + ?? + ?? + ?? )
?? . 
18.  Simplify: (v ???????? - v ?????? )
?? 
19. How many digits are there in the square root of 15625? 
20. How many digits will be there in the square of 999? 
21. Find the value of 
v
???? +
v
???? +
v
?? ?? + v ?? 
22. Find the value of 
v
???? -
v
???? +
v
???? - v ?? 
23. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? + ???? 
24. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
25. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? 
26. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
27. Find the value of (?? × ?? ) + (?? × ?? ) + (?? × ?? ) + (?? × ?? ) 
28. Find the value of (???? )
?? - (???? )
?? . 
29. Find the value of v???? × v ???? 
30. What is the sum of first 14 odd natural numbers? 
31. Find X and Y if (?? )
?? = ?????? such that ?? > ?? , where X and Y are positive 
integers. 
32. If length of a rectangular park is 80 m and its breadth is 60 m. find the sum of 
length of its diagonals. 
33. Evaluate: (?? + v ?? )
?? + (?? - v ?? )
?? . 
34. Find the least number that should be subtracted from 537 to get a perfect 
square. 
35. If the area of a square is 20.25 sq. m, find its perimeter. 
Page 3


  
 
 
Square and Square Roots 
Points to Remember 
? A Natural number x is a perfect square if there exists a natural number y such 
that x=y
2
. 
? A number ending in 2, 3, 7 or 8 is never a perfect square. 
? The number of zeros in the end of a perfect square is never odd. 
? Square of even numbers are always even. 
? Square of odd numbers are always odd. 
? Sum of first ?? natural numbers= 
?? (?? +?? )
?? 
? Sum of first ?? natural even numbers=?? (?? + ?? ) 
? Sum of first ?? natural odd numbers=?? ?? 
? The square of a natural number other than 1 is either a multiple of 4 or exceeds 
a multiple of 4 by 1. 
? The square of a natural number other than 1 is either a multiple of 3 or exceeds 
a multiple of 3 by 1. 
? For any number ?? greater than 1, (?? ?? , ?? ?? - ?? , ?? ?? + ?? )is a Pythagorean triplet. 
 
QUESTIONS 
1. How many perfect squares lie between 100 and 1000? 
2. Write the smallest four digit perfect square number. 
3. Find the value of x, if (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
4. Simplify:v ???? × ?? + ???? × ?? 
5. Simplify:
v
(?? . ???? ) + v ?? . ???????? 
6. Simplify:
v
?????? +
v
?? + v ???? 
7. Simplify:v???????? × v
????????
?? .????
 
8. Find the value of (?????? )
?? - (?????? )
?? 
9. Simplify: ?? ?? - ?? ?? + ?? ?? - ?? ?? + ?? ?? 
  
 
10. Simplify:(v?????? ÷ ?? )
?? 
11. Simplify:v?????? + v ?? . ???? 
12. Simplify:v
?? ???? .?? 
13. How many 2’s are there in the prime factorization of 4000? 
14. Find the least number that should be added to 221 to get a perfect square. 
15. If area of a square field is 1764 sq. m. Find its perimeter. 
16. How many numbers lie between (???? )
?? and (???? )
?? ? 
17. Find the value of(???? + ?? + ?? + ?? + ?? + ?? )
?? . 
18.  Simplify: (v ???????? - v ?????? )
?? 
19. How many digits are there in the square root of 15625? 
20. How many digits will be there in the square of 999? 
21. Find the value of 
v
???? +
v
???? +
v
?? ?? + v ?? 
22. Find the value of 
v
???? -
v
???? +
v
???? - v ?? 
23. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? + ???? 
24. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
25. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? 
26. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
27. Find the value of (?? × ?? ) + (?? × ?? ) + (?? × ?? ) + (?? × ?? ) 
28. Find the value of (???? )
?? - (???? )
?? . 
29. Find the value of v???? × v ???? 
30. What is the sum of first 14 odd natural numbers? 
31. Find X and Y if (?? )
?? = ?????? such that ?? > ?? , where X and Y are positive 
integers. 
32. If length of a rectangular park is 80 m and its breadth is 60 m. find the sum of 
length of its diagonals. 
33. Evaluate: (?? + v ?? )
?? + (?? - v ?? )
?? . 
34. Find the least number that should be subtracted from 537 to get a perfect 
square. 
35. If the area of a square is 20.25 sq. m, find its perimeter. 
  
 
36. Find the least number by which 288 must be multiplied so that it becomes a 
perfect square. 
37. Find the least number by which 147 must be divided so that it becomes a perfect 
square. 
38. The area of a square field is ????
?? ?? sq. m. Find the length of the side of the square. 
39. Find the length of a side of a square playground whose area is equal to the area 
of rectangular field of dimension 72m and 50m. 
40. Find the value of 
v?????? -v ??????
v?????? +v ??????
 
41. Find:  9+11+13+15+17+19+21+23 
42. How many perfect squares lie between 0 and 550? 
43. Find the value of 
v
v
????????
????????
 
44. Find the value of (???? + ?? )
?? - (???? - ?? )
?? 
45. Find the value of (v ?????? - v ?????? + v?????? - v ???? ) 
46. Find the missing number: ?????? × ___ = (???? )
?? 
47. Find the Pythagorean triplet whose smallest number is 12. 
48. Find ?? if, ?? ?? = (???? )
?? - (???? )
?? 
49. Find ?? if, ?? = v ?? . ???? + ?? . ???? + ?? . ???? + ?? . ???? + ?? . ???? 
50. Find ?? if, ?? = (?? + ?? v?? )(?? - ?? v?? ) 
 
 
 
 
 
 
 
 
 
 
 
 
 
Page 4


  
 
 
Square and Square Roots 
Points to Remember 
? A Natural number x is a perfect square if there exists a natural number y such 
that x=y
2
. 
? A number ending in 2, 3, 7 or 8 is never a perfect square. 
? The number of zeros in the end of a perfect square is never odd. 
? Square of even numbers are always even. 
? Square of odd numbers are always odd. 
? Sum of first ?? natural numbers= 
?? (?? +?? )
?? 
? Sum of first ?? natural even numbers=?? (?? + ?? ) 
? Sum of first ?? natural odd numbers=?? ?? 
? The square of a natural number other than 1 is either a multiple of 4 or exceeds 
a multiple of 4 by 1. 
? The square of a natural number other than 1 is either a multiple of 3 or exceeds 
a multiple of 3 by 1. 
? For any number ?? greater than 1, (?? ?? , ?? ?? - ?? , ?? ?? + ?? )is a Pythagorean triplet. 
 
QUESTIONS 
1. How many perfect squares lie between 100 and 1000? 
2. Write the smallest four digit perfect square number. 
3. Find the value of x, if (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
4. Simplify:v ???? × ?? + ???? × ?? 
5. Simplify:
v
(?? . ???? ) + v ?? . ???????? 
6. Simplify:
v
?????? +
v
?? + v ???? 
7. Simplify:v???????? × v
????????
?? .????
 
8. Find the value of (?????? )
?? - (?????? )
?? 
9. Simplify: ?? ?? - ?? ?? + ?? ?? - ?? ?? + ?? ?? 
  
 
10. Simplify:(v?????? ÷ ?? )
?? 
11. Simplify:v?????? + v ?? . ???? 
12. Simplify:v
?? ???? .?? 
13. How many 2’s are there in the prime factorization of 4000? 
14. Find the least number that should be added to 221 to get a perfect square. 
15. If area of a square field is 1764 sq. m. Find its perimeter. 
16. How many numbers lie between (???? )
?? and (???? )
?? ? 
17. Find the value of(???? + ?? + ?? + ?? + ?? + ?? )
?? . 
18.  Simplify: (v ???????? - v ?????? )
?? 
19. How many digits are there in the square root of 15625? 
20. How many digits will be there in the square of 999? 
21. Find the value of 
v
???? +
v
???? +
v
?? ?? + v ?? 
22. Find the value of 
v
???? -
v
???? +
v
???? - v ?? 
23. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? + ???? 
24. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
25. Find the value of ?? + ?? + ?? + ?? + ???? + ???? + ???? + ???? + ???? + ???? 
26. Find the value of x if, (?? )
?? + (?? )
?? + (???? )
?? = (?? )
?? 
27. Find the value of (?? × ?? ) + (?? × ?? ) + (?? × ?? ) + (?? × ?? ) 
28. Find the value of (???? )
?? - (???? )
?? . 
29. Find the value of v???? × v ???? 
30. What is the sum of first 14 odd natural numbers? 
31. Find X and Y if (?? )
?? = ?????? such that ?? > ?? , where X and Y are positive 
integers. 
32. If length of a rectangular park is 80 m and its breadth is 60 m. find the sum of 
length of its diagonals. 
33. Evaluate: (?? + v ?? )
?? + (?? - v ?? )
?? . 
34. Find the least number that should be subtracted from 537 to get a perfect 
square. 
35. If the area of a square is 20.25 sq. m, find its perimeter. 
  
 
36. Find the least number by which 288 must be multiplied so that it becomes a 
perfect square. 
37. Find the least number by which 147 must be divided so that it becomes a perfect 
square. 
38. The area of a square field is ????
?? ?? sq. m. Find the length of the side of the square. 
39. Find the length of a side of a square playground whose area is equal to the area 
of rectangular field of dimension 72m and 50m. 
40. Find the value of 
v?????? -v ??????
v?????? +v ??????
 
41. Find:  9+11+13+15+17+19+21+23 
42. How many perfect squares lie between 0 and 550? 
43. Find the value of 
v
v
????????
????????
 
44. Find the value of (???? + ?? )
?? - (???? - ?? )
?? 
45. Find the value of (v ?????? - v ?????? + v?????? - v ???? ) 
46. Find the missing number: ?????? × ___ = (???? )
?? 
47. Find the Pythagorean triplet whose smallest number is 12. 
48. Find ?? if, ?? ?? = (???? )
?? - (???? )
?? 
49. Find ?? if, ?? = v ?? . ???? + ?? . ???? + ?? . ???? + ?? . ???? + ?? . ???? 
50. Find ?? if, ?? = (?? + ?? v?? )(?? - ?? v?? ) 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
ANSWERS 
Question No. Answer Question No. Answer 
1.  21 26.       ?? = ???? 
2.  1024 27.  40 
3.        ?? = ???? 28.  120 
4.  12 29.  66 
5.  0.3 30.  196 
6.  18 31.        X= ???? , Y= ?? 
7.  1000 32.  200 m 
8.  3003 33.  14 
9.  15 34.  8 
10.  9 35.  18 m 
11.  10.3 36.  2 
12.  
      
?? ????
 
37.  3 
13.  5 38.  5.5 m 
14.  4 39.  60 m 
15.  168 m 40.          
?? ????
 
16.  124 41.  128 
17.  625 42.  23 
18.  1 43.  
         
?? ?? 
19.  3 44.  528 
20.  6 45.  10 
21.  6 46.  7 
22.  7 47.  12,16,20 or 12,35,37 
23.  143 48.  93 
24.          ?? = ???? 49.  0.6 
25.  110 50 1 
 
Read More
83 videos|70 docs|36 tests

Top Courses for Class 8

83 videos|70 docs|36 tests
Download as PDF
Explore Courses for Class 8 exam

Top Courses for Class 8

Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Related Searches

Mental Maths Questions and Answers: Square and Square Roots | Mental Mathematics for Class 8

,

shortcuts and tricks

,

Viva Questions

,

Exam

,

Important questions

,

study material

,

ppt

,

MCQs

,

practice quizzes

,

Summary

,

Previous Year Questions with Solutions

,

Objective type Questions

,

video lectures

,

Semester Notes

,

Mental Maths Questions and Answers: Square and Square Roots | Mental Mathematics for Class 8

,

Extra Questions

,

past year papers

,

pdf

,

Sample Paper

,

Free

,

Mental Maths Questions and Answers: Square and Square Roots | Mental Mathematics for Class 8

,

mock tests for examination

;