School #12 was a school for boys in Lodz. The students in #12b attended classes in the afternoon. Most students were between 10 and 15 years old, meaning that they were born between 1926 and 1931.
School #12 was located at Ulica Franciszkańska 29. The street name was changed to Franzstrasse when German occupation began in 1939. You can read more about the schools on Ulica Franciszkańska at
http://www.lodz-ghetto.com/the_schools_and_collective_prague_IV.html,26.