FINDING THE SQUARE ROOT OF A NUMBER WHICH IS A PERFECT SQUARE
Mathematics can be an amazing subject if we can observe and find some relationships between numbers and find a solution. Today I am going to write about finding the square root of the number..
What is the square of any number?
The answer to this question is when we multiply the number by itself we get the square of the number. For example if we multiply 4 with 4 itself we get 16. This is nothing but creating 4 groups of 4 objects and putting these together.
so 4×4 =16 and this can be written as 42.
The square root is just the reverse of finding the square. to find the square root of any number we need to find the number which multiplies by itself to give us that big number. In this post I am going to show how to calculate the square root of any perfect square if you remember the squares between 1 to 9. To help memorize I am giving you the squares of the numbers between 1 to 9
12 =1, 22 =4, 32 =9, 42 =16, 52 =25, 62 =36, 72 =49
82 =64, 92 =81, 102 =100
Once we know this we can start our calculations of finding the square root of any perfect square.
Lets take an example of 3969.
The first thing to do is to divide the number in 2 parts. Keep the right most two digits ( here that will be 69) and keep the remaining digits in one group.
In the next step find out the squares that end with 9. Here we have two such squares
32 =9
72 =49
so for the unit place of our answer we have two choices 3 and 7.
Now take the other portion which is 39. Find out the number that is a perfect square and is nearer to 39. From our table we see that such number is 62 =36 as 72 =49 is bigger that 39.
So we have the answer as 6 for this. However for the unit place we still have the 2 choices 3 and 7. To find which one is the correct choice take the answer that we just got i.e 6 and multiply it with the next number which is 7
6×7 =42 and 42> 39 so for our unit place we will go for the smaller number which is 3 and we have the answer as 63
The below flow chart makes it more clear
Few things to remember
- when you multiply a number it has to be the number you got as an answer for the ten’s place
- The number needs to be multiplied by the next number i.e if you have found the number for the right group as 7 then it needs to be multiplied by 8.
- You should remember your tables from 2 to 10 perfectly. ( to practice on the tables you can buy my practice sheets from the shop)
- While comparing the number that you have found through multiplication compare it always to the group that you have formed on the left side
- If the number after the multiplication is bigger than the number on the left then select the smaller number if it is smaller then select the bigger number.
Download the free practice sheets from our download section and try to find the answers… Do write to us on a2yacademy@outlook.com