Khan Academy could expand into preparation for various Olympiads such as the IEO and IMO. It's units and modules would be of a great help, along with practice questions to check the student's understanding of each unit and an ultimate practice test to check for all concepts. As an 11th grader, I cannot find any resources except the SOF workbook to prepare for the exam. It would be great if Khan Academy could help in the preparation for the same for grades 10 to 12 to begin with.