Every digit to the right of the millions place becomes zero.
45 000 000
Now you need to decide if the 5 remains as a 5 or if it goes up to a 6. In the original number, look at the first digit to the right of the 5. If it is from 0 to 4, the 5 remains as 5. If it is from 5 to 9, the 5 goes up 1 to 6.
45620 000
The first digit to the right of the 5 is a 6, so the 5 in the millions place goes up to 6.
