To calculate \( \left( \frac{1}{3} \right)^3 \), you multiply \( \frac{1}{3} \) by itself three times:
\[ \left( \frac{1}{3} \right) \times \left( \frac{1}{3} \right) \times \left( \frac{1}{3} \right) = \frac{1 \times 1 \times 1}{3 \times 3 \times 3} = \frac{1}{27} \]
So, \( \left( \frac{1}{3} \right)^3 = \frac{1}{27} \).