What is 5 1/4 as an improper fraction?

To convert the mixed number 5 1/4 to an improper fraction, follow these steps:

1. Multiply the whole number by the denominator: 5 × 4 = 20
2. Add the numerator to the result: 20 + 1 = 21
3. The improper fraction is 21/4

So, 5 1/4 as an improper fraction is 21/4.