How to find a Square root of a number?

The first method is inter-related to this one. This method is applicable only for perfect squares. You have to follow Three simple steps. 1.Find the range2.Check the Unit Digit.3.Find the square of number ending with 5 in the particular range and fix thenumber. a)What is the square root of 484?Step 1 We all know 202 = 400. Also we know 302 = 900. So our number lies between 20 and 30. Step 2 The unit digit is 4. So the unit digit of square root can be either 2 or 8. The number can be either 22 or 28. Step 3 Between 20 and 30, we can easily find the square of 25 using the first method. 252 = (2 x 3)25 = 625 484 is less than 25. So Answer is 22. b)What is the square root of 9801?Range – 90 to 100. Square of 95 = (9 x 10) 25 = 9025. Answer can be either 91 or 99. (Based on Unit Digit) 9025 is less than 9801. So 99 is the Answer

How to find the square of number ending with 5

1. How to Find the Square of Number ending with 5? We know  • 52 = 25 • 152 = 225 • 252  = 625 Now see the similarity. In all these numbers the last two digits are same. That is 25. The only thing it changes is the first digit.  How to find that? a) What is 152? We know the last two digits of the square will be 25. Now take the first digit of 15; i.e. 1. Multiply 1 with it’s next number. i.e. 2. So 1 x 2 = 2. Answer is 225.  b) What is 252? We know the last two digits of the square will be 25. Now take the first digit of 25; i.e. 2. Multiply 2 with it’s next number. i.e. 3. So 2 x 3 = 6. Answer is 625.  c) What is 552? (5 x 6) 25 = 3025 d) What is 852? (8 x 9) 25 = 7225. Hardly it takes less than 5 seconds. You don’t even need to write the numbers on the paper.  Try 1052 As usual (10 x 11) 25 = 11025 is the answer. Our usual method will take a minimum of 30 seconds to do this simple multiplication. Now we can easily save 25 seconds.     Practice Problems 1. 1152 2. 2052