School #13 was a school for boys in Lodz. The students in #13a attended classes in the morning. Most students were between 8 and 12 years old, meaning that they were born between 1929 and 1933.
School #13 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.