Answer:
9,000,000
Explanation:
To round numbers you look at the number to the RIGHT of the place value you want to round to.
In this case, you want to round to the nearest million and 8 is in the millions place.
Look to the right of 8, and it is 6. If the number is 5 or more then round the number in the millions place UP, if it is 4 or less round the number in the millions place DOWN.
Since 6 is 5 or more, make the 8 a 9 and all the remaining numbers after that become zeros.
8,632,051 becomes 9,000,000. This makes sense because this is 9 million, with no other numbers that aren't in the millions place.