The document discusses square roots and real numbers. It defines square roots as the number that when multiplied by itself equals the original number. Numbers with whole number square roots are called perfect squares. Most numbers are not perfect squares and have irrational square root values that are non-terminating decimals. The combination of rational and irrational numbers make up the set of real numbers. The document provides examples of finding square roots with and without a calculator and identifying the whole number a square root lies between.