Skill: Simplify square roots of perfect squares

A square root asks: What nonnegative number, multiplied by itself, gives the number inside the radical?

To simplify $\sqrt{n}$:

1. Recognize whether $n$ is a perfect square.
2. Find the nonnegative number whose square is $n$.
3. Write that number as the answer.

Example: Simplify $\sqrt{144}$.

Find a number that squares to $144$:

$$12^2=12\cdot 12=144$$

Because a square root means the principal nonnegative square root,

$$\sqrt{144}=12$$

Notice that $(-12)^2$ is also $144$, but $\sqrt{144}$ is $12$, not $-12$, because square roots are defined to be nonnegative. Similarly, $\sqrt{0}=0$.