ABSTRACT
We have focused our attention mostly on properties of integers: divisibility, primes, and congruences. Before we leave the topic of number theory, we want also to explore the properties of rational and irrational numbers. To begin, we explore the relationship between fractions and decimals. Then we consider the set Q itself and ask how large this set is. Finally, we move on to the rest of the real numbers, or the irrationals, and ask how many of them there are.
