 So far we've reviewed how multiplication and division work in decimal and seen how they also work in binary. But it's not going to be quite so easy if we're interested in doing multiplication and division in some arbitrary base. It turns out to be harder because we depend on knowing a times table to do our multiplication and division. We may not be able to look up everything directly out of that times table, but we know that we can get a lot of the basic information that we need. In decimal we've memorized this times table. In binary it was just very simple. You only had zeros and ones to work with. So in this section we're going to start by building a times table, and then we'll go back and see how we can use that times table to do multiplication and division in that base.