“…It is important to support students" ability to think algebraically in the elementary grades in order to help middle and high school students from not experiencing difficulties in algebra (Cai, Ng, & Moyer, 2011). More specifically, the studies about learning algebra in the early grades show that students generally have difficulty in manipulating algebraic expressions (e.g., Banerjee & Subramaniam, 2012;Booth, 1988;Gunnarsson, Sönnerhed, & Hernell, 2016;Livneh & Linchevski, 2007;MacGregor & Stacey, 1997;Seng, 2010). Gallardo (2000) asserts that there is a didactic cut in the child"s thought in the transition from arithmetic to algebra and that students have a resistance to operating with unknowns in the transition to algebraic thinking.…”