National Institute of Adult Education ව්යාපාර සංඛ්යානය: පංති කාමර ඇගයීම = wyapara sankyanaya (a.po.sa usas pela) - Maharagama: National Institute of Education, 1997. - 71p.; 28cm ISBN: 9555974500 Subjects--Topical Terms: Mathematics Dewey Class. No.: 519.5 / WAY