Split parents and children into two single-file lines (or four lines to have a races) across the width of the court from each other. Start by having one person carry a beanbag or ball on her racquet to the first person in line across the court and transfer the beanbag (without touching it by hand) to the other person’s racquet. That player carries it back to the other side again. The relay continues until everyone has had a specified number of turns.