In early 2020, due to the COVID-19 outbreak in Malaysia, all higher education institutions had to switch from face-to-face learning to open and distance learning (ODL) method. The main purpose was to prevent any further spread of the COVID-19 virus. This study aimed to identify factors carrying impacts on students’ satisfaction in learning calculus using ODL method. The sample consists of 224 students of Universiti Teknologi MARA (UiTM) Perak Branch, Tapah Campus who took calculus subjects using ODL method during the COVID-19 lockdown in Malaysia. Five factors are found to influence students’ satisfaction towards ODL method: student-lecturer interaction; lecturer performance; ODL course evaluation; design; and technical. By using partial least square (PLS)–SEM method, the results showed that lecturer performance has a large effect size on students’ satisfaction. Technical and design factors have medium effect sizes, while the ODL course evaluation and student-lecturer interaction have small effect sizes. This research provided useful insights for an effective planning of online calculus courses by considering all factors that influence students’ satisfaction.

Evaluation of the questions’ level of complexity for the statistical course was proposed using the revised version of Bloom’s taxonomy. The use of Bloom's taxonomy in statistical examination papers allows the degree of difficulty to be pseudo-objectively assessed. Well-constructed questions in the final examination will help in measuring students' abilities based on comprehensive cognitive skills. Therefore, this study used Rasch Model to evaluate the quality and reliability of final exam questions for probability and statistics course. According to research findings, five out of 30 questions are considered as misfit items. It is therefore recommended that these items be removed or rephrased to better suit the students’ ability level in a course. Whereas, nine questions have significant differences between taxonomy level and Rasch level that require further analysis. Overall, students view the set of exam questions as simple due to the unavailability of difficult items. Based on this result, it is suggested that the exam questions should undergo verification process from the expert and students should be exposed early to various types of questions with different level of difficulty.

Calculus has always been issue of underachievement performance for public university students. Insufficient background of SPM Additional Mathematics affected the students' performance in Mathematics at university level. One of the main reasons that contribute to this problem is the lack of understanding of the basic concept in differentiation and integration. Two innovative techniques of basic differentiation and integration for trigonometric functions by using mnemonic chart are developed in this paper. Many students face difficulties to memorize the formulas which unable for them to solve the given problems. These proposed techniques minimize students' problem in memorizing formulas as well as improve teaching method for educators. In addition, these new technique is not only can be advantageous for university students in Calculus course, but also for Matriculation and STPM students in Mathematics subject. This technique emphasizes square and triangle shape to be used for Original Rule and Chain Rule. All formulas can be derived from clockwise and anticlockwise direction. In the future, further research need to be done whether mnemonics are effective and useful to academic programmes such as Science-based programmes and also for secondary high schools.