You would be split into 3 groups (year 7's) or 4 groups (year 8's) named 7A, 7B, 7C, (year 7s) and 8A, 8B, 8C, 8D (year 8s), and these groups would be created within your house.
juː wʊd biː splˈɪt ˌɪntʊ θɹˈiː ɡɹˈuːps jˈɪɹ sˈɛvən z ɔːɹ fˈoːɹ ɡɹˈuːps jˈɪɹ ˈeɪt z nˈeɪmd sˈɛvən ˈeɪ, sˈɛvən bˈiː, sˈɛvən sˈiː, jˈɪɹ sˈɛvən z ænd ˈeɪt ˈeɪ, ˈeɪt bˈiː, ˈeɪt sˈiː, ˈeɪt dˈiː jˈɪɹ ˈeɪt z, ænd ðiːz ɡɹˈuːps wʊd biː kɹiːˈeɪɾᵻd wɪðˌɪn jʊɹ hˈaʊs.