Our first kind of infinity comes up when we try to work out the answer to the question ‘how many?’ For instance, if we ask how many positive whole numbers there are below 3, the answer is ‘2’. But what about if we ask how many whole numbers there are in total? What about all rational numbers? Not surprisingly, we get the answer ‘infinity’. But what may be surprising is that we can make sense of saying one of this kind of infinity is ‘bigger’ than another! In fact, there are infinitely many of this kind of infinity – the first few are represented by the Hebrew letter א, Aleph, as shown below.