I personally find the best way to deal with such numbers is to talk about nines.
999,999,999 in a billion=99.9 999 999%= 9 nines
999,999,999,999 in a trillion=99.9 999 999 999%= 12 nines
I personally find the best way to deal with such numbers is to talk about nines.
999,999,999 in a billion=99.9 999 999%= 9 nines
999,999,999,999 in a trillion=99.9 999 999 999%= 12 nines