Question

what set of numbers does -7 belong too

Answer 1

Natural numbers.

Answer 2

It also would be an integer.

Answer 3

Not natural.

Answer 4

Natural numbers (counting numbers):
{1, 2, 3, ... }

Whole numbers (zero added to the natural numbers):
{0, 1, 2, 3, ... }

Integers (negatives of the natural numbers added to the whole numbers):
{ ..., -3, -2, -1, 0, 1, 2, 3, ... }

Answer 5

-7 is an integer.
-7 is also a rational number.
-7 is also a real number.