This document discusses Piaget's and Vygotsky's theories of cognitive development and their implications for teaching practices. Piaget's theories suggest that teachers should use concrete examples, hands-on activities, and familiar contexts tailored to students' developmental levels. For pre-operational children, instruction should be explicit, involve interactions, and provide a variety of experiences. Concrete operational children benefit from continued hands-on learning and logical problem-solving. Formal operational students can explore concepts and hypotheses. Vygotsky's zone of proximal development theory implies assessment and instruction should start at students' current ability levels and provide support and motivation to progress further. Teachers should encourage collaboration and apply lessons to real-world experiences.