To divide two fractions, you can multiply the first fraction by the reciprocal of the second fraction.
So, to calculate \(\frac{3}{10} \div \frac{1}{3}\), you can rewrite this as:
\[ \frac{3}{10} \times \frac{3}{1} \]
Now, multiply the numerators and the denominators:
\[ \frac{3 \times 3}{10 \times 1} = \frac{9}{10} \]
Therefore, \(\frac{3}{10} \div \frac{1}{3} = \frac{9}{10}\).