I've always wondered the significance of circumambulating the Navagraha (Pradakshina). And why Nava - graha (Nine - Realms)? Almost all temples have them, but most people I talk to give mythological explanations, which I am skeptical of, since I believe the sages had other more deep scientific reasoning behind it.
Another thing that had always been a mystery to me (and I am sure to most people) is the symbol "0" for zero.
We know the zero is an invention of the Hindus, forming part of the decimal numbering system, but what was the evolution of the symbol?
The first clue for me came from this video from Rebecca Newburn
Now consider this: One pradakshina is passing through 9 grahas right? How do you graphically represent one circle? "0"! Now comes the best part - one pradashina is 9 grahas, what happens if you pass the next graha? 1 graha past 0, right? 10! To check - if you go round three times, you pass (literally) 27 grahas right? Plus 3 more grahas - 3 grahas past 0, right? 30!
So 40 grahas is actually 4 grahas past the end of the circle (0) four times (which is 4 X 9 plus 4 more grahas). More importantly, in the Vedic Math usage, any and each number can be contained within the Navagrahas.
In Ms Newburns video, we actually see the usage of this containment. I have used this effectively in my lectures. One example is here.
Now there are other secrets of the Navagraha that I wish to explore...