Improving children's "number sense" has been a core component of recent mathematics curricular and instructional reforms (CCSS, 2010; NCTM, 2000, 2014) in the United States. Students with mature number sense make sense of numbers and operations, use reasoning to notice patterns, and flexibly select the most effective and efficient…

Existing literature on the impact of Common Core State Standards in Math has shown little benefit, but it has not examined variation in outcomes based on implementation strategies, student subgroups, or outcomes other than test scores. We use a difference-in-differences approach with school fixed effects to compare outcomes in pre- and…

The subject of this report is a pair of written, group-administered tests designed to measure the performance of grade 1 and grade 2 students at the beginning of the school year in the domain of number and operations. These tests build on previous versions field-tested in fall 2013 (Schoen, LaVenia, Bauduin, & Farina, 2016). Because the tests…

Gridley Unified School District serves just over 2,000 students across five schools in a small rural town in the upper Sacramento Valley. The median annual household income in Gridley is just over 60% of the state average. Gridley Unified is one of seven districts studied by researchers at the Learning Policy Institute in a mixed-methods study…

Sitting just north of the U.S.-Mexico border, the Chula Vista Elementary School District (CVESD) supports teaching and learning in California's largest elementary school system. Across its 47 schools, CVESD educators serve over 30,000 students each day, 90% of whom are students of color and over one third of whom are English learners. CVESD is one…

Long Beach Unified School District (LBUSD) has been nationally recognized as a consistently high-functioning district for more than 2 decades. The district educates approximately 72,200 students, from preschool to high school, in its 86 schools. Almost 90% are students of color, with 57% Latino/a and 12% African American, while 65% are from…

The San Diego Unified School District (SDUSD) supports teaching and learning in California's second-largest school district, educating students from preschool to high school each day. Nearly three quarters of SDUSD students are students of color, including 47% who are Latino/a and 9% who are African American. Almost 60% of students are…

Located just southeast of Fresno in California's Central Valley, Sanger Unified School District (USD) serves approximately 12,000 students in 20 schools. Sanger USD students are predominately from low-income families (73%); most are Latino/a (70%), and about one in five (18%) are English learners. During the accountability era of No Child Left…

Serving a working-class suburb of the Los Angeles metropolitan area, the Hawthorne School District (HSD) is a small district with 11 schools: seven elementary schools, three middle schools, and one dependent charter high school. HSD's students are predominantly from low-income families (87%). Most students (71%) are Latino/a and about fifth (21%)…