Dividing Fractions · Superchallenge problem

Plan A: cut a $10$-foot pipe into pieces $1\tfrac{1}{4}$ feet long, then cut each of those pieces into as many $\dfrac{1}{2}$-foot pieces as possible, throwing away any scraps. Plan B: cut the $10$-foot pipe straight into $\dfrac{1}{2}$-foot pieces. How many more $\dfrac{1}{2}$-foot pieces does Plan B give than Plan A?