To express $\frac{31}{90}$ as a recurring decimal, we divide 31 by 90:

$31 \div 90 = 0.3444444\ldots$

So, $\frac{31}{90} = 0.34\overline{4}$.

This means the decimal repeats the digit "4" after the first two digits.

Would you like further details on this process, or have any questions?

Here are 5 related questions you may find helpful:

1. How do you convert any fraction to a recurring decimal?
2. What is the difference between terminating and recurring decimals?
3. How do you identify the length of a repeating sequence in a recurring decimal?
4. Can recurring decimals always be written as fractions?
5. How do you convert a recurring decimal back into a fraction?

Tip: When dividing to find a decimal, recognize recurring decimals by spotting repeating digit patterns in the quotient.