Spreadsheets are a core computational tool for practicing engineers and engineering students. While Microsoft Excel, Google Sheets, and other spreadsheet tools have some differences, numerous formulas, functions, and other tasks are common across versions and platforms. Building upon learning science frameworks showing that interactive activities are advantageous, an interactive textbook from zyBooks was created to provide students the opportunity to acquire spreadsheet skills by doing. Interactive components include stepping through animations, completing multiple choice and matching questions, and evaluating spreadsheet formulas and functions using 100+ auto-graded, randomized questions. While the interactive reading participation was discussed in previous work, the focus here is on auto-graded questions, sometimes called online homework. Fraction correct regardless of attempts, number of attempts before correct, and number of attempts after correct provided metrics to examine deliberate practice across three cohorts encompassing over 250 students. Sections grouped as General spreadsheet skills or Functions generally showed greater median correct, ranging from 76 to 90%, than sections categorized as Advanced spreadsheet skills, which led to median correct of 68 to 81%. Median correct also varied between different question types and decreased with question order, which aligns with questions being scaffolded. Finally, a hypothesis was tested: Adding a Copy sheet feature to the auto-graded questions would encourage deliberate practice and improve fraction correct between cohorts. Over 80% of students used the new Copy sheet button, and a statistically significant increase with large effect size in fraction correct between cohorts was found, which supports the hypothesis.