Math skills are critical to a variety of careers and important for life skills ranging from budgeting and smart shopping to understanding the news. The Pennsylvania Keystone Exam is one path for high school students to demonstrate readiness for postsecondary success. Proficiency among historically underperforming students can show whether districts and education policymakers have made progress in closing the achievement gap between traditionally underserved groups and other students.

In 2021, 73% of students in Lancaster County and 48% of students in the Lancaster City School District passed the Grade 11 algebra exam, representing a slight change from 74% in the County and up from 45% in the District in 2019. In contrast, 52% of historically underperforming students in Lancaster County and 43% of historically underperforming students in the Lancaster City School District passed the exam in 2021, down 2 percentage point in the County and up 3 points in the District in 2019. Lancaster County's 2021 proficiency rates were higher than statewide rates of 63% for all students and 42% for historically underperforming students.

Lancaster County has the highest proficiency rate among all students, followed by Chester (71%), Cumberland (69%), and York (66%) and the highest performance rate among historically underperforming students, followed by Chester and York (both at 46%) and Cumberland (44%). Lancaster County's share of historically underperforming students in eleventh grade (52%) is higher than Lebanon (42%), Dauphin (39%) and Berks (34%).

As assessments vary among states, it is not possible to include comparable data for the nation or other areas in this indicator. Data are from the Pennsylvania Department of Education.

2021 results may not reflect representative samples of the schools' students. Cross-year comparisons of proficiency are likely to be inaccurate for this reason.