To compare the two fractions, we need to determine their values.
- The fraction four-fifths is written as \( \frac{4}{5} \).
- The fraction \( \frac{16}{20} \) can be simplified by dividing the numerator and denominator by 4, which gives \( \frac{4}{5} \).
Since both fractions are equal (\( \frac{4}{5} = \frac{16}{20} \)), the correct phrase to insert is:
is equal to
Thus, the complete comparison is:
Four-fifths is equal to \( \frac{16}{20} \).