TUTORIALS:

Powers
Powers, or exponents begin
as shorthand notation for repeated multiplication. For example,
we write:
Here, 2 is called the base and 5 is called
the power or exponent. We
describe 2^{ 5} as meaning “2 raised to the power
5” here. The exponent applies only to the quantity to its
immediate lower left. Be careful indicating powers of negative
numbers. Brackets must be used:
(3)^{ 4} = (3) Ã— (3) Ã— (3) Ã— (3) = + 81
But, without the brackets
3^{ 4} =3 Ã— 3 Ã— 3 Ã— 3 =  81
Without the brackets, the power of 4 in 3^{ 4}
applies only to the 3, and does not include the minus sign.
