The old man has three grandsons and five great-grandsons.
Tips
memory
Walk the generations down: 子 zǐ (son) 孙 sūn (grandson) 曾孙 zēngsūn (great-grandson) 玄孙 xuánsūn (great-great-grandson). Here 曾 zēng means 'one generation removed', not 'once' as in 曾经 céngjīng - same character, different reading.
