The challenges Throughout the early years of life, children notice and explore mathematical dimensions of their world. They compare quantities, find patterns, navigate in space, and grapple with real problems such as balancing a tall block building or sharing a bowl of crackers fairly with a playmate. Math- ematics helps children make sense of their world outside of school and helps them construct a
solid foundation for success in school. In elemen- tary and middle school, children need mathemat- ical understanding and skills not only in math courses but also in science, social studies, and other subjects. In high school, students need mathematical proficiency to succeed in course work that provides a gateway to technological literacy and higher education [1–4]. Once out of school, all adults need a broad range of basic mathematical understanding to make informed decisions in their jobs, households, communities, and civic lives. Besides ensuring a sound mathematical foundation for all members of our society, the nation also needs to prepare increasing numbers of young people for work that requires a higher proficiency level [5, 6]. The National Commission on Mathematics and Science Teaching for the 21st Century (known as the Glenn Commission) asks this question: “As our children move toward the day when their decisions will be the ones shaping a new America, will they be equipped with the mathematical and scientific tools needed to meet those challenges and capitalize on those opportunities?” [7, p