The iPhone features a built in calculator application that allows you to perform basic scientific calculations. Using the calculator application's scientific mode you can calculate cubed roots.
A cubed root is a number that when multiplied by itself three times yields a given number. For example, the cubed root of 8 is 2 since 2 x 2 x 2 = 8.
Tap the "Calculator" application on your iPhone.
Rotate your iPhone to the horizontal or landscape position to activate the scientific features of the Calculator application.
Enter the number you want to find the cubed root of. For example, tap "8" to find the cubed root of 8.
Press the root key. You will find the root key in the third row, the third icon from the left.
Tap the "3" key to display the cubed root. Continuing the same example, the iPhone's Calculator application will display a "2."