This study attempts to reveal pre-service teachers' conceptions, definitions, and understanding of quadrilaterals and their internal relationships in terms of personal and formal figural concepts via case of the parallelograms. To collect data, an open-ended question was addressed to 27 pre-service mathematics teachers, and clinical interviews…

Children from southern and northern Brazil have a basic knowledge of plants, which they observe during their everyday life. Children ages between 3 to 10 years old (kindergarten & primary school), but the majority of them in the age group of 4-5 (total 145) were asked to draw what they think is a plant (total sample = 332). Afterwards, a equal…