This was the first modern treatment of trigonometry in the Chinese language. Ricci collaborated with Li Chih-tsao to produce T'ung-wen Suan-chih (literally, Combined Languages Mathematical Indicator), a general treatise on European arithmetic.
這是中國第一幅世界地圖，中國人從此才知道，中國並不在世界的中央，也才開始有了世界觀。