text: according to the website https://steinwald-schule-berlin.de, it's 7+9, not 7-9. The housenumbers in this street are ordered like that: 1, 3, 5, ... on the southern/western side; 2, 4, 6, ... on the other side of the road. The school can't have a housenumber 7 to 9 (7-9), but 7+9. A housenumber 8 is obviously not in use here.