### Theory:

The opposite of a positive integer is negative.
Example:
1. The opposite of $$5$$ is $$-5$$.

2. The opposite of $$10$$ is $$-10$$.
The opposite of a negative integer is positive.
Example:
1. The opposite of $$-3$$ is $$3$$.

2. The opposite of $$-24$$ is $$24$$.
The opposite of the opposite of a number is the number itself.
Example:
1. The opposite of $$-5$$ is $$5$$ and the opposite of $$5$$ is $$-5$$.
So, the opposite of the opposite number is the same number $$-5$$.

2. The opposite of $$10$$ is $$-10$$ and the opposite of $$-10$$ is $$10$$.
So, the opposite of the opposite number is the same number $$10$$.
The opposite of every positive number is the same number with a negative sign.
Important!
The opposite of $$0$$ is $$0$$. This is because zero is neither positive nor negative.