Square Of Number Ending With 5


 
 
Concept Explanation
 

Square Of Number Ending With 5

Rule 1: The square of a number of the form a5 (where a is tens digit and 5 is units digit) is the number which ends in 25 and has the number a(a+1) before 25 .

Rule 2: The square of a number of the form 5a (where a is units digit and 5 is tens digit) is equal to

(25+a)times 100+a^{2}

i.e. (5a)^{2}=(25+a)times 100+a^{2}

Rule 3: The square of a three digit number 5ab (where b is units digit and a is tens digit) is given by

(5ab)^{2}=(250+ab)times 1000+(ab)^{2}

Here ab stands for the number formed by the last two digits.

Rule 4:The square of a number abc...5(i.e. a number having 5 at unit's place is obtained by affixing 25 to the right of the number n(n+1),where n = abc...

Illustration: Find the square of 65.

Solution: The given number is 65 Hence it is of the form a5 where a = 6

               So a(a+1) = 6(6+1) =6(7) = 42

              Hence large (65)^{2}=4225

Illustration: Find the square of 85.

Solution: The given number is 85 Hence it is of the form a5 where a = 8

                 So a(a+1) = 8(8+1) = 72

                  Hence large (85)^{2}=7225

Illustration: Find the square of 125.

Solution: The given number is 125 Hence it is of the form a5 where a = 12

                So a(a+1) = 12(13) = 156

                Hence large (125)^{2}=15625

Illustration: Find the square of 527.

.... (More Text Available, Login?)
Sample Questions
(More Questions for each concept available in Login)
Question : 1

The square of 1235 is ___________________.

Right Option : B
View Explanation
Explanation
Question : 2

Find the square of 115.

Right Option : A
View Explanation
Explanation
Question : 3

Find the square of 524.

Right Option : A
View Explanation
Explanation
 
 


Students / Parents Reviews [20]