It has been observed that students shy away from the study of Mathematics even though it is a back bone of science and technology. This is confirmed by the negative attitude and poor performance of students in Mathematics especially at primary colleges' level. It is this background that prompted the research into the problems faced by lecturers and students in teaching and learning of "approximation" in primary colleges of education. The study was aimed at identifying problems and suggesting measures to improve performance. The study adopted the descriptive survey design using simple frequency and percentages in analyzing data. Stratified and simple random sampling techniques were used to select one hundred and ninety eight (198) students from four (4) randomly selected colleges of education on the Copperbelt Province and eighteen (18) lecturers were purposively selected from the same colleges. Data were collected by means of two questionnaires administered to students and lecturers. The five (5) points' Likert-type rating scale was adopted for the questionnaire responses which was of the types, strongly agree, agree, neutral, disagree and strongly disagree. Some of the findings that emerged were related to personality of the lecturers, characteristics of students, nature of the curriculum, learning environments and government policies on education. Based on these findings, it was recommended that (i) the government should endeavor to provide the necessary infrastructure and facilities that will motivate teaching and learning of mathematics. (ii) Government should send lecturers for training and seminars for effective teaching and learning. The researcher recommended that colleges should invest in improving the classroom environment by reducing the lecturer-student ratio and offer incentives to lecturers in colleges of education.