CLASS 8 OCTOBER REVISION RATIONAL NUMBERS SQUARES AND SQUARE ROOTS

 CLASS 8

OCTOBER REVISION

RATIONAL NUMBERS

SQUARES AND SQUARE ROOTS


1. Using appropriate properties find.


(i) -2/3 × 4/7 + 5/2 –  4/7 × 1/6


2. Multiply 18/11 by the reciprocal of - 9/55


3. Represent  -3/7, -5/7 and -9/7  on the number line.


4. Find the rational numbers between -2/5 and  1/4.


5. What will be the unit digit of the squares of the following numbers?


i. 679

ii. 2723

 

6. Find ten rational numbers between 2/7 and 3/5.

 

7. Without adding, find the sum.


 1 + 3 + 5 + 7 + 9


8. Express 49 as the sum of 7 odd numbers.

 0

9. How many numbers lie between squares of the following numbers?

i. 12 and 13


10. Find the square of the following numbers.


 (i)  32  (ii) 78


11. Find the square roots of 100 and 169 by the method of repeated subtraction.

 

12. Write a Pythagorean triplet whose one member is 6.


13. find the smallest whole number by which it should be multiplied so as to get a perfect square number. Also find the square root of the square number so obtained.

(i) 252  (ii) 1200

4

14. Find the square roots of the following numbers by the Prime Factorisation Method.

i. 729

ii. 400

iii. 1764

iv. 4096


15. For each of the following numbers, find the smallest whole number by which it should be divided so as to get a perfect square. Also find the square root of the square number so obtained.


i. 2925

ii. 396


5

16. 2025 plants are to be planted in a garden in such a way that each row contains as many plants as the number of rows. Find the number of rows and the number of plants in each row.

 

17. Find the smallest square number that is divisible by each of the numbers 4, 9 and 10.


18. Find the square root of the following numbers by Division method.

(i) 2304

(ii) 4489

(iii) 3481

(iv) 529

(v) 3249


19. Find the square root of the following decimal numbers.

i. 2.56

ii. 7.29

iii. 51.84 


20. Find the least number which must be subtracted from each of the following numbers so as to get a perfect square. Also find the square root of the perfect square so obtained.

i. 402

ii. 1989

iii. 3250


21. Find the least number which must be added to each of the following numbers so as to get a perfect square. Also find the square root of the perfect square so obtained.

(i) 525

(ii) 1750

(iii)1825

(iv) 6412


22. In a right triangle ABC, ∠B = 90°.

a. If AB = 6 cm, BC = 8 cm, find AC


 



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