Influence of Instructional Materials in Eradicating Errors in Children's Number Work in Pre-Schools in Kamukunji Sub-County, Nairobi County

The study investigated the effect of instructional materials in eradicating reflection errors and number omission errors. The population of the study involved 450 children from 15 pre-schools which had been selected by random sampling. The research design used was Quasi experimental. It had both control and experimental group and the data was analysed by means of frequencies and percentages. The study was based on constructivist theory by John Dewey. The study had sought to achieve the following objectives: (i) The pretest performance of control and experimental group (ii) The posttest performance of both control and experimental group (iii) The relationship between performance of the two groups. The data showed that the control group in both pretest and posttest made many errors while the experimental group which had used instructional materials made few errors and performed better. The findings of the study in the pretest and posttest of the control group in reflection errors recorded 76.5 % and 72.5 % respectively. There was a 4 % improvement. The pretest and posttest of the Experimental group in reflection errors recorded 73.5 % and 16.5 %. There was 57 % improvement. The pretest and posttest for number omission errors in control group showed 68.5 % errors and 64.5 % respectively. There was a 4 % improvement. The pretest and posttest for the Experimental group in number omission errors recorded 64.5 % and 21.5 %. There was 43 % improvement. The study recommended use of adequate and age appropriate materials during instruction. Children should be discouraged from copying other childrens work in order to avoid transferring mistakes to their work.