Proving that a given set is indeed a subgroup, one needs to show that it is non-empty, and closed under operation and inverses. This study focuses on the first condition, analysing students' responses to this task. Results suggest that there are three distinct problematic responses: the total absence of proving this condition, the problematic…

Pam Shanks describes the stages in the child's development of language and reminds us that the Montessori principle of observation should guide the support of the child with articulation errors. For most children with developmental articulation delays, the directress can implement Montessori materials and use conversational strategies to emphasize…