Answer:
There are nine 0's in a billion, six 0's in a million, five 0's in hundred thousands, four 0's in ten thousands, three 0's in thousands, two 0's in hundreds, and one 0 in tens...
Use this formula and put your numbers in from largest to smallest:
800 000 000 000 <- 800 billion
800 000 000 <- 800 million