# How do you find the square root of 3.24?

Notice how $324$ is a perfect square. $\sqrt{324} = \pm 18$. Therefore...
$\sqrt{3.24} = \sqrt{\frac{324}{100}} = \frac{\sqrt{324}}{\sqrt{100}} = \pm \frac{18}{10} = \textcolor{b l u e}{\pm 1.8}$
You can check by determining that $\sqrt{3} = 1.732$ and $\sqrt{4} = 2$, and $1.8$ is between them, while being closer to $1.732$, corresponding to $3.24$ being closer to $3$ than to $4$.