Development of early math skills is an important part of elementary schooling and a foundation for continuing progress in not only math, but also science and related subjects. 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, 50% of students in Lancaster County and 20% of Lancaster City School District students scored as proficient or advanced on the PSSA Grade 3 Math exam, down from 59% in the County and 37% in the District in 2019. In comparison, 32% of historically underperforming students in Lancaster County and 17% of historically underperforming students in the Lancaster City School District passed the exam, down from 44% in the County and 35% in the District in 2019. Lancaster County's 2021 proficiency rate was above the statewide rate for both groups (which was 47% for all students and 29% for historically underperforming students).

Compared with surrounding counties, Lancaster County has the third highest proficiency rate among all students following Chester (59%) and Cumberland (55%) and the second highest performance rate among historically underperforming students following Cumberland County at 34%. Lancaster County's share of historically underperforming students in third grade (32%) is higher than Chester (31%), York (30%), Lebanon and Berks (both at 22%), and Dauphin (21%).

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.

The Spring 2020 PSSA was cancelled in March 2020 due to the Covid-19 pandemic. 2021 PSSA results were delayed. 2021 results may not reflect representative samples of the schools' students. Cross-year comparisons of proficiency are likely to be inaccurate for this reason.