In order to round the number to 2 significant figures, let's round the third digit from the left to the right, this way we keep only the two more significant digits from the left.
Since the third digit is 9, we will round the second digit up.
This way the second digit changes from 9 to 0, adding one more unit to the first digit, which is 7 and then becomes 8.
Therefore the rounded value is 8000.