This is a continuation of the previous post about the 11 Principal. I'll start by explaining with 9, 99, 999, and beyond, then extend to base-1, base²-1, base³-1, and beyond. Finally, why the 11 principal

An easy way to see if a number can be divided evenly by 11 is by following a few easy step. Choose a number. Add every other digit together. Then add the rest of the digits together. Subtract one of these