Integers are rounded in exactly the same way as whole numbers are rounded, because negative sign (minus sign) doesn't influence process of rounding.
So, we just go through a couple of examples.
Example 1. Round -456 to the nearest ten.
Since last digit is greater or equal then 5 (it is 6), then we round up: 56 becomes 60.
Example 2. Round -45678 to the nearest thousand.
Since last three digits (678) form a number that is greater then 500, then we round up: 5678 becomes 6000.
Example 3. Round -486 to the nearest hundred.
Since last two digits form a number that is greater than 50 (it is 86), then we round up.
Now, take a pen and paper and solve following problems.
Exercise 1. Round -156 to the nearest ten.
Exercise 2. Round -456748 to the nearest ten.
Exercise 3. Round -13456 to the nearest hundred.