The document defines perfect squares and square roots. It provides examples of calculating perfect squares up to 152 and identifying which numbers are perfect squares. It then discusses how to find the square root of a number by factoring it into smaller perfect squares. The document also explains how to estimate square roots for non-perfect squares by interpolating between the closest perfect squares on a number line. It gives examples of estimating the square root of 27 and 18. Finally, it covers properties of square roots, including that the square root of a negative number is not real and the order of operations with radicals.