The first step is to understand what it means when a number has an exponent. The “power” of a number indicates how many times the base would be multiplied by itself to reach the correct value.
The second step is to write the number in the base-exponent form, and lastly calculate what the final result would be. Consider the example of 2 to the power of 4: in exponent form that would be
So re-applying these steps to our particular problem, we first convert our word problem to a base-exponent form of:
To simplify this, all that is needed is to multiply it out:
91 x 91 x 91 x 91 x ... (for a total of 18 times) = 183123913839120657539940631629904921
Therefore, 91 to the power of 18 is 183123913839120657539940631629904921.