Figured out a pretty basic but neat trick while practicing — sharing here in case it gives someone else the same “aha!” moment it gave me:
If you need to find a 4th root on the GRE calculator (which doesn’t have an nth root function), just take the square root twice.
Example:
To compute 814\sqrt[4]{81}481:
→ First, √81 = 9
→ Then, √9 = 3
That’s your 4th root!
Simple, fast, and super useful for simplifying radicals on test day. Hope it helps!