Full Text Article. Also available at: http://journals.univ-danubius.ro/index.php/research/article/view/4437The study assesses teacher’s use of logic in teaching and students' assignments, exercises, group work, test and examination. Every University in Tanzania has its own teachers' training curriculum; the way teachers are educated to meet challenges and still upholding teaching qualities is questionable. The study involved qualitative (focus group discussion and observation of students assessments) and quantitative (structured interview) design. The study noted that; majority of teachers lack sufficient logical knowledge of subject matter and do code switch between English and Swahili in teaching although Swahili is not language of instructing science subjects. The study revealed that teacher's use of logic in teaching and student’s assessment is not good and requires understanding of subject matter. Respondents recommend the use logic in the students’ assessment from simple to complex problems as logical skill acquisition. Something lacking in learners is problems solving skills, they rely on reading and memorizing solved questions instead of making logic from what they were taught. The study contributes significantly to understanding of students' learning and understanding as well as the teachers' teaching and students' assessing skills.