Students often panic when they see these problems for the first time. Fractional exponents are just another form of notation for expressing powers and their relationship to roots. When we look at the fractional exponent, the numerator is equal to the power and the denominator is the equivalent of the root index. With this in mind, any base raised to a one-third exponent is actually a cube root. Likewise any base that is raised to a one-half power is actually a square root. The fractions involved may be positive, negative, or even improper. Answers may be fractions or whole numbers.
These worksheets explain how to evaluate expressions with fractional exponents.