How could you cut a piece of dough into $3$ even pieces? Cutting it into $2$ is easy, but it's not that trivial for greater numbers.
If you can cut it into $n$ pieces, you could repeat the process on each piece, getting any multiplication of $n$, so to ask a more general question:
Let $p\in\mathbb{N}$ be a prime number. How can you cut a piece of dough into $p$ pieces?
P.S. I couldn't find a good tag, any bright idea?