* Look at the tens digit: The tens digit is 2.

* Consider the ones digit: The ones digit is 9. Since 9 is greater than or equal to 5, we round the tens digit up.

* Round the tens digit up: 2 becomes 3.

* Replace the tens and ones digits with zeros: The result is 1600.

Therefore, 1629 rounded to the nearest 100 is 1600.