Mwangi SW. Effects of Concretised Geometrical Models during Instructions on Secondary School Students’ Mathematics Achievement by Gender in Kibwezi Sub-county, Kenya. theijhss [Internet]. 2017 Jun. 30 [cited 2024 Jul. 23];5(6). Available from: https://internationaljournalcorner.com/index.php/theijhss/article/view/125419