Cube, roots

2nd F and the recall key give $\displaystyle x^{3}$. Type 8, press and , and press : 512.. The root key is the square root. For any other root, type the index first, then 2nd F and the power key. Press the , type 49, press the , and press . Type 4, press and , type 81, and press . $\displaystyle \sqrt{49} - \sqrt[4]{81}$ is 4.. The key with the root key gives the . Type 27 and press : 3..