Is there anyway to format a decimal in fractions: 1/3 rather than .333?
Python has a module to work with fractions, so you can achieve this using a formula column. I put together a quick example here: Fractions - Grist.
The relevant formula there is:
from fractions import Fraction
str(Fraction($Value).limit_denominator())
You can read up on the Python Fraction class here: fractions — Rational numbers — Python 3.10.7 documentation.