> To explain the idea to a child, I would focus on the principal idea: whether finite or infinite, a number is even when it can be divided into pairs. For finit

> To explain the idea to a child, I would focus on the principal idea: whether finite or infinite, a number is even when it can be divided into pairs. For finite sets, ..... Pretty sure if I tried to explain this to my kid niece she'd just say: "I'm uncomfortable. Can I go now?"