Aidan McCann, 13, dreamed up a push cart with height adjustment features to help his grandmother Lydia who "isn't very strong". He witnessed how the pint-sized 75-year-old finds it difficult to carry groceries from the shops and perform other physically demanding tasks due to her height. But Aidan came up with a solution -- a trolley that "can change heights so elderly people don't have to lift their bags very far". The primary school pupil scribbled down the idea and it was so good: it won him the top award in a national engineering competition.