2 ** 3 = 2 * 2 * 2 = 8
2 ** -3 = 1 / (2**3) = 0.125
2.5 ** 3 = 2.5 * 2.5 * 2.5 = 15.625
2.5 ** -3 = 1 / (2.5**3) = 0.064
-2.5 ** -3 = -0.064
2**3 * 2**3 = 8*8 = 64
2**(3*2)**3 = 2**(6**3) = 1.0531229166856E+65