Suppose we have some number a, the degree of which is the number n. To build a number to a power means to multiply the number a to itself n times.
Consider a few examples.

To build the number 2 in the second degree, you must produce action:

To build the number 3 in the fifth degree, you must take action:

There is no generally accepted designation of the second and third degree numbers. The phrase "second degree" is usually replaced by the word "square" instead of the phrase "the third degree" usually say "cube".
As can be seen from the above examples, the duration and the complexity of calculations depends on the magnitude of the exponent of the number. Square or cube – a relatively easy task; raising a number to the fifth or greater degree already requires more time and accuracy in calculations. To accelerate this process and to avoid errors, you can use a special mathematical tables or a scientific calculator.