“…The studies of intellectual functioning are addressing skills such as attention and understanding (Rezaiyan et al, 2007), working memory (Delavarian et al, 2015), punctuation and comprehension (Segatto et al, 2017), and cognitive skills (Siberski et al, 2014;Tsimaras et al, 2014). Also, the study regarding performing recycling tasks is included, because the feature of problem solving is mainly presented in the study by Chang et al (2014).…”