“…Although children's understanding of the commutativity and inversion principle has received much research attention (e.g., Bisanz, Watchorn, Piatt, & Sherman, ; Canobi, Reeve, & Pattison, ; Gaschler, Vaterrodt, Frensch, Eichler, & Haider, ; Gilmore & Bryant, ; Gilmore & Papadatou‐Pastou, ; Gilmore & Spelke, ; Godau, Haider, Hansen, Schubert, & Gaschler, ; Piatt, Matejko, Watchorn, & Bisanz, ; Prather & Alibali, ; Rasmussen, Ho, & Bisanz, ; Robinson & Dubé, ; Siegler & Stern, ), only few studies investigated children's understanding of the other principles, particularly the addition/subtraction complement principle (e.g., Baroody, ; Canobi, , , ; Dowker, ). This is surprising because a good understanding of the addition/subtraction complement principle is assumed to enhance mathematical proficiency, specifically the application of the subtraction by addition strategy (Baroody et al ., ).…”