17/8 = 2.125
She will need 3 packs of hotdog buns to make sure they have enough for the guests
It would equal 5 x 10 ^ 10
because 10 ^ 10 is 10 billion and 9 x 10 billion is 90 billion and 4 x 10 billion is 40 billion. so, 90 billion - 40 billion. that's 50 billion, and that can be turned into 5 x 10 ^ 10.
