Howdy, Teresa.
When we round, we look at the digit in that place. If the number after it is 5 or greater, the number goes up. If the number after it is 4 or less, the number stays the same.
Anything before the digit you changed or didn't change stays the same. Everything after that digit turns to zeroes.
The millions place is the 0 before the first comma. The next number is 8, which is more than 5, so the 0 changes to a 1. The 7 and 5 before it stays the same, and everything after our new 1 turns to 0.
Our answer is 751,000,000.
I hope this helps!
Teresa P.
11/04/14