Oh, dude, rounding 109 to the nearest 100 is like, super easy. You just look at the tens place, which is zero, and since it's less than 5, you don't need to do anything. So, 109 rounded to the nearest 100 is still 100. Easy peasy, lemon squeezy.
110
109 dollars.
1,499,999,999 will round to the nearest billion to get 1091,000,499,999 will round to the nearest million to get 109, and so on.
110
110
100
372 rounded to the nearest hundred is 400
300
100
10100
4198 to the nearest 100 = 4200
The answer is zero.