The K-5 Mathematics Module Number and Number Sense is designed to assist elementary school teachers in implementing the 2009 Mathematics Standards of Learning. This module provides a sample of meaningful and engaging activities correlated to the number and number sense strand of the kindergarten through grade five mathematics Standards of Learning. The purpose of the Number and Number Sense module is to enhance teachers’ content knowledge and their use of instructional strategies for teaching the number and number sense strand.Through explorations, problem-solving, reasoning, and hands-on experiences, teachers will engage students in activities that address many dimensions of number and number sense including counting, combining, sorting, comparing sets of objects, comparing whole numbers, rounding of numbers, and exploring place-value and fraction and decimal concepts to develop number understanding.By using these activities, it is anticipated that teachers will develop new instructional techniques to assist them in increasing student mathematics achievement in the classroom.