Mental Math and an Out of the Body Experience (OBE) - Part 1

During my college years I practiced multiplication problems in my head. At the time, I was interested in trying to hone my skills and see if I had a hidden savant in me. As a result of my efforts, I developed a method for mental multiplication. In this two part series, I will present the following:

1. A method for multiplying large numbers in your head
2. An Out of the Body Experience (probably as a result of squaring a 12 digit number)

So, here I will explain my method for mental multiplication gymnastics. Practice is required. Probably a few multiplication problems each day will suffice. We will start with multipying 2 digit numbers, then 4, then 8 and finally 12 digits. The reward may be more than you bargained for. My OBE was my first and my last. Since the event, I have not been interested in multiplying large numbers in my head. The experience was amazing and frightening at the same time. In my case, the fear is more powerful than the curiosity. Now for the first part.

Initially, you can start by writing down the multiplication problem on paper. For example:

                       37
                    x  81
                    -----

This way you will not have to memorize the numbers in your head. Later, with practice you should be able to visualize the whole problem in your head.

To make memorization easier, I use an inverted pyramid pattern for number placement. Also, I work from left to right. In the above example, the spaces for the partial multiplications is as follows:

           3 7                  3 7
        x  8 1               x  8 1
        ------  OR:           ------  
          AABB                 AABB
           CC                  CCC  
           DD

To get the value AA, just multiply the left 2 digits, 3x8 = 24, BB is 7x1= 07. Always keep 2 digits when multiplying, not 7, but 07 to help reduce errors. The CC and DD is generated from the cross product 8x7 and 3x1. Initially, you can do the two products seperate, but later, I recommend you add them in your head to get CCC as in example above. So, at this point you will have AA,BB,CC, and DD memorized in your head. The next part, adding them together, is trickier. So, now add AA and left side of the CC and DD to make a new AA. Then, add the BB to the right side of the CC and DD. If there is a carry, add it to the new AA. You have now completed the problem. The more you practice, the faster you will get and after awhile, it will be very easy.

The next step is to no longer use paper. Remember the numbers, and do the calculation in your head.

Once you have mastered the 2 digit problems, it is time to go to 4 digit problems. See example below:

                 3 7 4 2
              x  8 1 5 6
             -----------
               AABBCCDD
                EEFFGG
                 HHII
                  JJ

Now there are more cross products. You will be quick to create the first row of 24072012, as you have practiced a lot already. You now have to remember this 8 digit number and start on the cross products of the second row. I do this left to right again... 3x1+8x7=59, then 7x5+1x4=39, and 4x6+5x2=34. Now add 593934 to the original number. Proceed by adding left to right again. 24+5=29, 07+93=100, ... immediately carry the one and make it 30. Then, 20+93=113, ...immediately carry to make 2nd number 01. And, finally 12+40=52. The number to remember now is 30011352. To get the third row, we skip a digit in the cross
product. It will be 3x5+8x4=47 and 7x6+1x2=44. This one is easier to add, the result is 30485752. Finally, we do the outer cross product 3x6+8x2=34 and add it to make 30519752.

Obviously, the method is not perfect, as in regular multiplication, the carries in the addition are problematic. This is my method, maybe you can come up with a better method. Please let me know.

After practicing the 4 digit problems it is easier to go to 8 digit problems. I follow the same pattern. First, do the single digit products to get a 16 digit answer. Then, do the cross products, and add them to the original result. Then do the cross products that skip one digit and add. Repeat this process for up to skipping 5 digits. Then, finally do the outer cross product. This is a lot to do in your head and a lot of memory usage. Like in a marathon, you do not need to do 8 digit multiplications as often. Mostly, concentrate on the 4 digit products for awhile. Once you have completed a few 8 digit multiplications, you might, if you dare, try the 12 digit product.

I discovered that I could not reach the savant level. Probably because the practice was sort of a meditation. And it did result in an out of the body experience that I will describe in part 2 of this report.