Multiplying Fractions · Challenge problem

Ella worked out $3\dfrac{1}{2} \times 2\dfrac{1}{2}$ like this: $3 \times 2 = 6$ and $\dfrac{1}{2} \times \dfrac{1}{2} = \dfrac{1}{4}$, so the answer is $6\dfrac{1}{4}$. Her method is wrong. By how much is her answer too small? Give your answer as a mixed number.