Choose the correct sign to compare the two fractions. Use the models to help.

To compare the two fractions, one-third \(\left(\frac{1}{3}\right)\) and \(\frac{5}{6}\):

1. **Convert to a common denominator:** The denominators are 3 and 6. The least common denominator (LCD) is 6.
- To convert \(\frac{1}{3}\) to a fraction with a denominator of 6, we multiply both the numerator and the denominator by 2:
\[
\frac{1}{3} = \frac{1 \times 2}{3 \times 2} = \frac{2}{6}
\]

2. **Now compare \(\frac{2}{6}\) and \(\frac{5}{6}\)**:
- Since \(\frac{2}{6}\) represents a smaller quantity than \(\frac{5}{6}\), we have:
\[
\frac{2}{6} < \frac{5}{6}
\]

Therefore, the correct sign to use is:

\[
\frac{1}{3} < \frac{5}{6}
\]