Answer :

If the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up (+1).

If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down (no change).

[tex]\boxed{6\underline{8}1,542\approx700,000}[/tex]