Look at the hundreds place. It has a 5 in its place. The rule for rounding is that if the number directly to the right of the place you are rounding is 4 or below, you round down. If it's 5 or above, you round up.
It has a 5 in its place, so we round up. The 5 becomes a 0, and the 1 in the thousands place becomes a 2. All other places are 0 because the rounding up affects all other places.