The number 9 features an interesting phenomena I will reveal for you in this very simple example.

9 x 1 = 9
9 x 2 = 18, but 1 + 8 = 9
9 x 3 = 27, but 2 + 7 = 9

See the pattern ? All multiples of 9 equal 9. It is the only number that does this.

What's also striking is that the pattern is revealed no matter how large the multiple.

9 x 333 = 2997 ( 2 + 9 + 9 + 7 = 18 ... and 1 + 8 = 9 ! )
578329 × 9 = 5204961 (5 + 2 + 0 + 4 + 9 + 6 + 1 = 27 and so 2 + 7 = 9)
482729235601 × 9 = 4344563120409 (4 + 3 + 4 + 4 + 5 + 6 + 3 + 1 + 2 + 0 + 4 + 0 + 9 = 45 and of course 4 + 5 = 9)

And that's your interesting math fact for today... but wait.. is there more to the significance of the number 9 ?

 

More Significant Facts About the Number 9

Take any number. Add up it's digits. Now, subtract the sum from the original number. Take this new number and add up it's digits. You will get a multiple of nine every time. Here is an example, let's start small with 25.

2 + 5 = 7; 25 - 7 = 18; 1 + 8 = 9

And how about a number such as 742.

7 + 4 + 2 = 13 and 742 - 13 = 729;
7 + 2 + 9 = 18 and 1 + 8 = 9 !

The sum of the digits in 742 equal 13. Then subtract 13 from 742. You get 729. So 7 plus 2 plus 9 equals 18. And of course 1 + 8 equals 9.

A beautiful pattern of nines prevail throughout mathematics, and this could be clue to the structure of our universe. In fact, it has inspired at least one man to claim that the number 9 is the mathematical fingerprint of god.

 

Why was Tesla convinced that the numbers 3, 6, and 9 are a key to the universe ?
Here's an interesting equation to ponder:

(9 x 1) + (9 x 2) + (9 x 3) + (9 x 4) + (9 x 5) + (9 x 6) + (9 x 7) + (9 x 8) + (9 x 9) = 405;

4 + 0 + 5 = 9;

405 - 9 = 396