Runmai, Yodthida, and Wasana Keeratichamroen. 2024. “A Study of Learning Achievement on Addition and Subtraction of Numbers up to 20 Learning Unit and Group Working Behaviors of Grade 1 Students using Team-Games-Tournament with Bar Model”. Ratchaphruek Journal 22 (1). ์์Nakhon Ratchasima, Thailand:129-43. https://doi.org/10.14456/rpjnrru.2024.9.