Answer
Rational numbers, integers, whole numbers, natural numbers.
Work Step by Step
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.
