1, online shopping platform: For example, Taobao, JD.COM and other e-commerce platforms have a large number of fourth-grade mathematics application-related products for sale. They can choose the right goods to buy according to their own needs.

2. Educational apps: Some educational apps also provide related resources for the first volume of mathematics application problems in the fourth grade, such as homework help.

3. Physical Bookstore: Some large chain bookstores, such as Xinhua Bookstore, will also sell books related to the first volume of fourth-grade math application problems.

4. Library borrowing: If you only need to consult some topics temporarily, you can consider borrowing relevant textbooks and reference books from local public libraries.