How to Easily Square Numbers Having 5 as the Last Digit

Now for this istudy technique for your studies, I am going to teach you how you can square (x²) any numbers that are having 5 as the last digit.

Even though squaring numbers won't take that long to solve, still it will take sometime to finish and it will also take some space on your scratch paper during your exam, quiz or just a normal on the spot test.

Did you ever think that you can easily square numbers having 5 as the last digit, e.g. 1025, 925, or even 25?

By the way what is the process of SQUARING A NUMBER first?

According to WIKIPEDIA "In mathematics, a square number or perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, 9 is a square number, since it can be written as 3 × 3."

Now to start with this istudy technique, follow the very easy and simple steps below.

How to Easily Square Numbers Having 5 as the Last Digit

Example A : 
1. Let us begin with the simple number 25. We knew that squaring this number manually will lead to the computation below :

2. Now to square 25 more easily and more faster follow the technique illustrated below.

STEP 1 : Immediately write 25 as the last two digit of your answer.

STEP 2 : Now ADD 1 to the 2 of the number 25(multiplier). You will get 3, then multiply 3 with the 2 of the remaining number 25(multiplicand). That would be 3(2) which is 6.

STEP 3 : Get the answer obtained by multiplying 3 x 2 which is 6 and write it as the first digit of your answer which will be 625.

Therefore 25 x 25  = 625.

Example B : 

Note that you can also use this technique for numbers 15, 25, 35, 45, 55, 65, 75, 85 and 95. Now, try to square the number 95. Yes! the answer will be 9025, which is definitely lightning fast answer. How did we get it?

Here's how;

Like the first example just write down 25 as the last two digit of your answer. Then add 1 to 9 and multiply it with the other 9 getting the equation of (9+1) x 9 = 90. Write 90 as the first 2 digits for your answer. Therefor 90 and 25 will produced 9,025 which will be your answer.

Example C :

As you will noticed numbers like 15, 25, 35, 45, 55, 65, 75, 85, and 95 are all can be easily squared mentally. Would you agree? How about the numbers that are having three digits and 5 as the last digit like 125, 675, and so on.

The process is just the same. For example we wanna square the number 775. Immediately write down 25 as the last two digit of your answer. Then Add 1 to 77 getting 78 and multiply it by 77 which will be 6006. Therefore the answer will be 600, 625.

Even though multiplying 78 and 77 will also take sometime. It is still more faster way to get the square of 775.

I have made my personal approximation of SECONDS spend using the manual squaring of the number 775 and the technique.

MANUAL SQUARING - about 45 seconds

USING THE TECHNIQUE - about 15 seconds

There is 30 seconds difference between the two ways of getting the square of the number 775. In an exam which is under pressure for having a time limit using this technique would be very beneficial.

NOTE :

• The same process goes with the four digit number.
• This technique is only tested for numbers having 5 only as the last digit.

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