[chief editors, Masami Isoda, Aki Murata, Aida Istino Yap ; editors of original Japanese edition, head of editors, Shin Hitotsumatsu, Yoshio Okada]. -- Gakkohtosho, [2015?]. -- (Study with your friends, mathematics for elementary school / [chief editors, Masami Isoda, Aki Murata, Aida Istino Yap] ; 6th grade, separate v.).