Dividing Mixed Numbers — Rules & Problems

Mary went to school with $5$ chocolate bars to share among her $7$ friends. When she got to school, she realized that her brother had already eaten $\frac{1}{2}$ of a bar! Now she was left with $4\frac{1}{2}$ bars to be divided among $8$ people (herself and $7$ friends). How much of a bar of chocolate would each person get if it were divided evenly?