AbstractThis study investigated the teaching methods used by the teachers in teaching pupils with low mathematical skills in Tanzania. The aim of this study was to introduce an effective intervention for enhancing pupils’ achievement levels in mathematics. The problem of low mathematical skills is caused by many reasons such as unsuitable teaching and learning environment, few teaching methods, negative attitude of pupils and parents towards mathematics, shortage of teaching and learning materials, negative interaction between teachers and pupils to mention few. Studies show that, pupils who experience learning difficulties may not be intellectually impaired; rather their learning problems may be the result of an inadequate design of instruction in curricular materials (Mathematics learning difficulties in primary education, 2008).This study used a qualitative approach which adopts a case study design. Also, the study adopted purposive sampling whereby four primary schools were selected and four teachers who teach mathematics in grade three from each school were the sample. Data were collected through observation and interview in which unstructured interview with open –ended questions were asked. The data obtained was analyzed following data through data reduction technique and presented through themes, sub-themes and short statements (Miles & Huberman, 1994). The analysis and interpretation of results was guided by the perspectives derived from three theories which are Vygotsky Cognitive Development Theory, Bronfernbrenner Ecological System Theory, Constructivism Theory and other studies from different literatures. The study shows two major findings: First, There were a large number of pupils in the classroom which caused teachers to fail to use different teaching methods. Second, There was a shortage of teaching and learning materials especially textbooks for both teachers and pupils. Two main recommendations of the findings are presented. Firstly, the findings point to the need to reduce the class size so as to enable teachers to accommodate every pupil in the mathematical classrooms. Secondly, there is a need to dedicate more teaching and learning text books for both teachers and pupils.