Gender: boy
School:
School #20B
A fuzzy search for 'K* Russek' turned up multiple results, but Kalman was the only one old/young enough to attend his school.
I matched Kalman to his parents (no siblings) via matching addresses. He had a father (Symcha, b. 1898) and a mother (Gitla, nee Stolnikowicz, b. 1890). They were all deported on March 27, 1942, during the month of daily deportations to Chelmno.