Supplementary Data for Instruction and Assessment without Calculators in an introductory microbiology course reveal student weaknesses in foundational quantitative literacy.

To preserve the integrity of exams after programmable calculators became ubiquitous, math-related microbiology exam questions were re-designed to allow for completion using only brief hand-written calculations and mental math. Students were advised at the beginning of the semester that lecture exams would be calculator-free, and were given questions for practice during and outside of class time. Although course prerequisites included high school math and chemistry, university-level chemistry and introductory genetics, students’ exam answers suggested unexpected weaknesses in quantitative literacy. Students were asked for permission to use their work in a six-semester study. Error analysis conducted on relevant assessment questions revealed difficulties with simple division, ratio set-up, dilution factors, unit conversions, concentration, and simple log and exponent calculations. During the final three semesters of the study, a simple preliminary math assessment was administered at the beginning of the course, to provide feedback to students and to determine whether their quantitative skills could be improved. A comparison of performance on the preliminary assessment questions versus relevant exam questions revealed that students could significantly improve their quantitative skills by the end of the course. This study is unique in its focus on calculator-free instruction, and assessment of fundamental quantitative literacy in post-secondary students.为保障可编程计算器普及后的考试公平性与完整性，与数学相关的微生物学考试题目被重新设计，仅允许考生通过简短的手写计算与心算完成作答。校方在学期伊始便告知学生，课堂考试不得使用计算器，并在课内与课外时段为学生提供了练习试题。尽管该课程的先修要求（prerequisites）涵盖高中数学、化学，以及大学层次的化学与入门遗传学，但学生的考试答卷暴露出他们在定量素养（quantitative literacy）方面出人意料的薄弱环节。本研究征得学生同意后，将其答卷纳入一项为期六个学期的研究中。对相关考评题目开展的误差分析显示，学生在简单除法、比例设定、稀释因子（dilution factors）、单位换算（unit conversions）、浓度计算，以及简单对数与指数运算（simple log and exponent calculations）等方面存在困难。在研究的最后三个学期，团队在课程开课之初便实施了一项简易的前置数学测评，以期为学生提供反馈，并评估他们的定量技能是否可得到提升。对比学生在前置测评与相关考试题目中的表现可知，学生可在课程结束时显著提升其定量技能。本研究的独特之处在于其聚焦于无计算器教学，以及对高等教育阶段学生（post-secondary students）的基础定量素养进行评估。