Evaluate square root of square root of 256

$\sqrt{\sqrt{256}}$

Step 1

Rewrite $256$ as $16^{2}$ .

$\sqrt{\sqrt{16^{2}}}$

Step 2

Pull terms out from under the radical, assuming positive real numbers.

$\sqrt{16}$

Step 3

Rewrite $16$ as $4^{2}$ .

$\sqrt{4^{2}}$

Step 4

Pull terms out from under the radical, assuming positive real numbers.

$4$