This book presents Mathematical approaches of teaching and learning Mathematics through problem-solving in a conducive mathematical classroom environment. The book embraced comparable methods of teaching Mathematics, but problem-solving takes supreme position in learning. The book practiced three important theories of education by three prominent personalities Paget, Bruner and Vygotsky. These are social constructivism, problem solving and production theories. These theories develop competent Mathematics communities who respond positively to transforming problem-solving activities necessary 21st century to attaining sustainable development goals.