Definition of Even Numbers
Definition
Simple Definition
A number is said to be even if it has a remainder of $0$ when divided by $2$.
Complex Definition
$$ a = 2 \cdot k $$ For any integer $a$, if there exists an integer $k$ that satisfies the above, then $a$ is considered Even. Integers that are not even are called Odd.
Explanation
There’s a question that reignites internet forums every cooldown period.
“Is $0$ even?”
The reason this sparks debate despite being taught in elementary school nationwide is simple. Many who are estranged from mathematics think with the premise of the ‘Simple Definition’ and that ‘$0$ cannot be divided’. Thus, fun banter ensues like “$0$ is a special number that is neither even nor odd” or “It’s a problem even Harvard hasn’t solved yet.” If you search ‘0 even’ on Google images, you can feel dizzy.
According to the Complex Definition, such questions are neatly terminated. The integer $0$ satisfies $$ 0 = 2 \cdot k $$ for $k=0$, making it unequivocally even. Not just that, but negative numbers like $-2$ and $-22$ are also even.