The study investigated the effects of extended teacher wait-time on senior secondary school students’ academic
achievement in mathematics in Asa High School in Ukwa-West Local Government Area of Abia State. The
research design employed to carry out this study was case study. A simple random sampling was used to select a
unit of SS1 intact class. The sample size was twenty. Three (3) research questions and two (2) hypotheses guided
this study. The instrument used for data collection was a non-participant observation technique in which video
recording was used to capture all the teaching sessions in phases 1 and 2. Frequency counts, phi-coefficient and
percentage mean were used to answer the research questions while chi-square statistics and t-test were used to
test the hypotheses at 0.05 alpha level with df =1 and 18 respectively. The result of the study showed that
mathematics teachers employed an insufficient teacher wait-time of less than 3 seconds, and that there is a
moderately positive relationship between students’ accuracy of responses and teacher wait-time. The result also
showed that there is a significant difference between the academic achievement of students taught mathematics
using insufficient and extended teacher wait-time and this difference was in favour of ETWT group. Based on
the findings of the study, it was recommended that mathematics teachers under training should be trained on the
effective use of extended teacher wait-time of between 3-5 seconds during micro-teaching and also inspectors
should lay emphasis on the use of Extended Teacher Wait-time (ETWT) when they go for classroom instruction
supervision