You can download it directly from Baidu. Search directly in Baidu, but the search here requires certain skills. We want to find the electronic version of the new fourth-grade math classroom in Qingdao. At this time, we need to search in Baidu like this: download the electronic version of the new fourth-grade mathematics classroom in Qingdao. The search method is book title+author (or publisher)+version (if any, which version needs to be written) +pdf (this must be added).