The square of 1980 is

• an even number

   

• an odd number

• a perfect number

Which of the following numbers would have digit 6 at unit place.

(i) 19² (ii) 24² (iii) 26²

(iv) 36² (v) 34²

What will be the “one’s digit” in the square of the following numbers?

(i) 1234 (ii) 26387 (iii) 52698

(iv) 99880 (v) 21222 (vi) 9106

The square of which of the following numbers would be an odd number/an even number?

Why?

(i) 727 (ii) 158 (iii) 269 (iv) 1980

What will be the number of zeros in the square of the following numbers?

(i) 60 (ii) 400

How many natural numbers lie between 92 and 10²? Between 11² and 12²?

Find whether each of the following numbers is a perfect square or not?

(i) 121 (ii) 55 (iii) 81

(iv) 49 (v) 69

Do you think the reverse is also true, i.e. is the sum of any two consecutive positive integers is perfect square of a number? Give example to support your answer.

The difference between the squares of two consecutive natural numbers is equal to the sum of the two numbers.