CCTV's documentary specially selected for children who are not good at math! CCTV's documentary specially selected for children who are not good at math! CCTV's documentary specially selected for children who are not good at math! CCTV's documentary specially selected for children who are not good at math! CCTV's documentary specially selected for children who are not good at math! CCTV's documentary specially selected for children who are not good at math!