A Mind-Blowing 3-Digit Number Squaring Shortcut

I'm frustrated and in want of some direction in life. I hate being here in University after two years of working as a technician in a semiconductor factory here in Malaysia. My problem is not the part where I have to study; it's more of the money-making that's tearing me apart from what I should do and what I have to do. In rough times like these, I turn to Jesus and He sends me a miracle drug that tranquilizes all of me and sets my foot right back on track. And what's the miracle drug? Basically, they are shortcuts to some of the meanest calculation problems in mathematics. I am impressed and I am sure you will be impressed to see how others might get impressed with this particular trick I have up my sleeves today.

In a previous article, I presented my method for squaring numbers whose tens digit was 5 and 9 respectively. Today, I am more than proud to present you with a mind-blowing method of squaring any 3 digit number whose tens digit is 5.

To begin with, I shall first introduce my canny friend, the Rules. It will be necessary to examine these rules in order to make your way about this method simpler. Since the tens digit has already been determined and defined to be 5, the next factor that would really affect the result of the square would be the value of the hundreds digit. Now this is where the rule comes in.

Step 1)
Assuming the three-digit number to be squared is written in algebraic form,
100a +10b+c, where b is defined as 5 and both a and c are any number from 1 - 9 and 0 - 9 respectively. First, we shall deal with a as in the following:

a x (a + 1); {this will give us the first one or two digits of the answer}

Step 2)
Next we shall obtain the following third digit and so on by performing the following:
25 + (2a + 1) x c; {this will give us the following digits of the answer. You may also assume that (2a +1) is the same as adding the number that comes right after a to a and multiplying that sum by the last the digit of the number to be squared}

Step 3)
Finally, we determine the last two digit of the answer simply by obtaining the square of c and read the results obtained in step1 and 2 followed by the one obtained in step 3 and that is the complete answer.

Here's another calculator tick off trick

Credit: Prince Prasad

Copyright: Princeton Prasad Pillai