To achieve the goal of 100% proficiency for all students in mathematics, a middle school in a large urban public school district in Omaha, Nebraska increased the frequency of instructional time in mathematics instruction for a group of seventh and eighth grade students. The purpose of this study was to determine if there was a difference in the performance of seventh and eighth grade students on the Nebraska State Accountability Mathematics Assessment (NeSA-M) using different frequencies of mathematics instruction, provided daily versus every-other-day. The Continuous Improvement Theory and Bloom's Mastery Learning model were used as frameworks to investigate math achievement. A quantitative causal-comparative study was conducted using ex post facto achievement data. The analysis included the comparison of the mean differences in NeSA-M scores for seventh and eighth grade students using an independent samples t test. This analysis was completed to see if block scheduling frequency daily versus every other day was effective with student achievement for each grade level. There were unexpected results from this study as the two grade levels demonstrated different effects from the influence of increased instructional time on the growth of middle school students' NeSA scores.