Hello!
When you round you look at the number to the right of where you are rounding and look to see what it is
If it is 5 or higher you round up
If it is lower than 5 you keep the number the same
You are rounding to the nearest 100
You look at the hundreds and tens place
1289
You look at the number to the right
Since it is higher than 5 you round the 2 up
The answer is 1300
Hope this helps!