# Ask for example: A simple ring with zero divisors

We know that a simple ring has characteristic either $$0$$ or a prime $$p$$. I am thinking about giving a concrete example of a simple ring WITH zero divisors.

I have found a reference talking about simple rings without zero-divisors:

A matrix ring $$M_n(R)$$ when $$R$$ is a simple ring, is also simple. For instance one can take $$R$$ to be one's favourite field. Matrix rings generally have zero divisors.