Question

Any number that is divisible by 4 is also divisible 8 counter example

Answer 1

The simplest example would be 4. 4 is divisible by 4, but not by 8, since
`\frac44=1\in\mathbb Z`, but
`\frac48=\frac12\\ot\in\mathbb Z`. (The quotient needs to be an integer)