Искакова М, Аяғанов Ғ, Даукен М. An effective way to detect the sum of the first n term of an arithmetic progression. P&P [Internet]. 2020Sep.30 [cited 2024May12];44(3):182-7. Available from: https://journal-pedpsy.kaznpu.kz/index.php/ped/article/view/105