Any multiple of 9, when the digits are added together until you're down to a single digit, will always end up at 9. amirite?

-46 Any multiple of 9, when the digits are added together until you're down to a single digit, will always end up at 9. amirite?

by Anonymous 1 week ago

This happens because we use a base 10 number system. In base 6 number system, 5 would have a similar property, for example.

by Anonymous 1 week ago

I've known that this happens for decades, but not why. And I still don't know why! Why does using base 10 cause this, or the equivalent in any other base?

by Anonymous 1 week ago

See the game 9 persons, 9 hours, 9 doors for Nintendo DS

by Anonymous 1 week ago

If its not £9, I'm gonna be gutted

by Anonymous 1 week ago