“Effectiveness of Universal Concept of Mental Arithmetic System (UCMAS) In The Developing Of Visual Thinking Among Fourth Grade Students (Quasi- Experimental Study In Private Schools At Lattakia)” (2017) Latakia University Journal - Arts and Humanities Sciences Series, 38(1). Available at: https://journal.latakia-univ.edu.sy/index.php/humlitr/article/view/2318 (Accessed: 29 August 2026).