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]207,689\approx210,000\\\\507,378\approx1,000,000\\\\3,422,087\approx3,422,000\\\\19,499,890\approx19,000000[/tex]