かけざん
かけざん · kakezan · JLPT N2 · noun
generation
掛け算 = 掛ける (to multiply) + 算 (calculation), so it means multiply-calculation
掛ける is the verb 'to multiply' (also 'to hang'). 算 means calculation or counting, the same kanji as 算数 (arithmetic). Multiplying is a kind of arithmetic.