The Effect of Virtual Manipulatives on Senior Secondary School Students' Achievement, Actual Understanding and Perceived Understanding in Geometry

This study examined the effect of Virtual Manipulatives on Senior Secondary School One students’ achievement, actual understanding, and perceived understanding in Geometry. A quasi -experimental, pretest-posttest, non-equivalent control group design was ado pted. Three co -educational schools were purposively selected. A total of 240 SS1 students participated: 120 in the Virtual Manipulatives group [66 males, 54 females] and 120 in the Traditional Method group. Data were collected using the Achievement Test [K R-20 = .83], Actual Understanding Test in Geometry [α = .84], and Virtual Manipulative Understanding Perception Scale [α = .81]. The experimental group was taught with GeoGebra applets for six weeks, two 40-min periods per week, while the control group received conventional instruction. Data were analyzed using means, standard deviations, and two-way ANCOVA at α = .05. Results revealed that students taught with Virtual Manipulatives had significantly higher posttest scores in achievement, F(1, 235) = 143.01 , p < .001, η² = .378; actual understanding, F(1, 235) = 120.47, p < .001, η² = .339; and perceived understanding, F(1, 235) = 89.62, p < .001, η² = .276, than the control group. There was no significant main effect of gender, nor interaction effect of method and gender on any outcome, p > .05. It was concluded that Virtual Manipulatives significantly improved students’ achievement, actual understanding, and perceived understanding in Geometry, with benefits consistent across gender. It was recommended that Mathematics teachers should integrate VM tools into instruction and that government should provide digital infrastructure in schools.