321 is an integer, so the closest integer would be 321. (If 321 itself doesn't count, 322 and 320 are the same distance from it, and are the next closest.)
20
321 is an integer and so there is no sensible way of writing it as a fraction or mixed number.
8 is an integer, so the answer is 8
An integer is a whole number so the answer is 4.
-132
No - an integer is a whole number - the closest integers to 12.5 are 12 and 13.
321 is an integer so 321
321 is an integer, not a fraction.
321 is an integer and so there is no sensible way of writing it as a fraction or mixed number.
No - 0.8 is a decimal number, not an integer. The closest integer is 1.
312 is not a sequence: it is a single 3 digit integer and one number cannot define a sequence.
8 is an integer, so the answer is 8
It is 18 or 20
An integer is a whole number so the answer is 4.
You can't write a non-integer as an integer. You can round it to the closest integer if you like, but it's not exactly the same number.
-132
You would round it to 25.
12