In 1920, when Roald Dahl was still only three years old, his seven-year-old sister Astri died from complications resulting from appendicitis. Only weeks later, Roald's father died of pneumonia aged 57, shortly before the birth of Dahl’s youngest sister. As the narrator of the book, Dahl suggests his father died of grief from the loss of his daughter. Roald's widowed mother was faced with the choice of moving the family back to Norway to be near to her family, or relocating to a smaller house in Wales to continue the children's education in the United Kingdom. She soon came to the decision to remain in South Wales, as she was determined that her children should be educated in English schools, as their father had always stated that English schools were the best in the world. Primary school Roald Dahl started at the Elm Tree House Primary School in Cardiff in 1921, when he was five years old. He was there for a year, but had few memories of his time there. Sweets Roald writes about different confectionery, his love of sweets, his fascination with the local sweet shop (11 High Street, Llandaff), and in particular, about the free samples of Cadbury chocolate bars given to him and his schoolmates much later when he was a pupil at Repton School. Young Dahl dreamt of working as an inventor for Cadbury, an idea he said later inspired Charlie and the Chocolate Factory, eventually published in the early 1960s. Some of the sweets he enjoyed as a child were lemon sherbets, pear drops, and liquorice boot laces. Great mouse plot of 1924 From the age of eight, Dahl attended Llandaff Cathedral School in Cardiff. He and his friends thoroughly disliked the local sweet-shop owner, Mrs Pratchett, an unpleasant, elderly woman who gave no thought to hygiene (and described by Dahl's biographer, Donald Sturrock, as "a comic distillation of the two witchlike sisters who, it seems, ran the shop in real life"). They played a prank on her by placing a dead mouse in a gobstopper jar while his friend Thwaites distracted her by buying sweets. They were caned by the headmaster as a punishment, after Mrs Pratchett identified Dahl and his friends as the pupils who were responsible for the mouse in the jar. Mrs Pratchett, who sat in the headmaster's office to watch the canings, was not satisfied after the first stroke