## Algebra 1: Common Core (15th Edition)

The number $\sqrt 16$ is equal to 4 because $4^{2}$=16. A natural number is a number in the set {1,2,3,4,…….}. Therefore, 4 and $\sqrt 16$ are in the set of natural numbers. The set of natural numbers is included in the sets of whole numbers, integers, and rational numbers as well. Therefore, $\sqrt 16$ is included in all of these subsets of real numbers.