The nth root of a number is that number which when raised to the
nth power (ie when multiplied by itself n times) results in the
number.
When n=2, it is the square root of the number;
when n=3 it is the cube root of the number.
To find the nth root of a number, an electronic calculator can
be used, using the nth root button [x√y] (though more recent
calculators replace the x and y by boxes) viz:
<n> [x√y] [2] [4] [4] [=]
or with the more recent calculators:
[#√#] <n> [Navigate →] [2] [4] [4] [=]
where <n> is the nth root, eg for 2nd root (square roots)
enter [2];
and the # is being used to represent a box on the keys of the
more recent calculator.
Considering the rules for indices, the nth root is the the
number to the power of 1/n, ie 244^(1/n), thus the calculation can
be done using the power button:
[2] [4] [4] [^] [(] [1] [÷] <n> [)] [=]
With the more recent calculators, the power button is pressed
first, the 244 entered, the navigate-right key pressed (to get in
to the power part of the input) and then the n entered.