This is a weird "something" that I found... 1. Choose a number. 2. Flip the number. 3. Take the difference of the two numbers. 4. That difference is... If the number is 2 digits long, the difference is the difference of the two digits in the number multiplied by 9. If it's three digits long, the difference is the difference of the last and first digit of the number multiplied by 99. If it's 4 digits long, it get's complicated. The difference is... Ugh. Okay, I'll make an equation. 1st,2nd, 3rd, and 4th stands for the digits in the number. 9 x (( | (((1st x 10) + 2nd) - ((4th x 10) + 3rd)) | x 10) + | 1st - 4th | |x| means absolute value of x. There. Now it's all out. Please try to make sense of it. Then there's 5 digits long. Equation: 99 x ( | (((1st x 100) + (2nd x 10)) - ((5th x 100) + (4th x 10))) | x 10) + | 1st - 5th | That's an even BIGGER equation, but it's simpler.
I stumbled across all of the equations when I was on a treadmill. So as far as I know, I'm the first to "discover" it.