To convert the mixed number 3 1/3 to an improper fraction, follow these steps:
1. Multiply the whole number by the denominator: 3 × 3 = 9.
2. Add the numerator to the result: 9 + 1 = 10.
3. The improper fraction is the result over the original denominator: 10/3.
So, 3 1/3 as an improper fraction is 10/3.