To confirm, you are asserting that the foundation for your answer (mathematical reasoning) does not require any mathematics to understand why it is true.

It’s very dangerous to take a reductionist approach and not be aware of the baked in assumptions you are using. For example, the terms even and odd (for this problem) are well defined as concepts for integers. Which means that your hand-wave statement is true as a result of definitions that were likely created to ensure this property held true.

The notion that “I don’t need math to understand why this is true” is like saying “I made an observation on a phenomenon and I don’t need science to know it’s true.” Which, as you are hopefully aware, is again reductionist and leads to a huge distrust of science from the science illiterate.