Some General Advice:
Most scholarships require letters of reference written by faculty members who know your work. (In this context, the term "advisor" means a faculty member who knows your work, either from class or research projects.) Since professors are asked to write many letters, you should confirm their willingness to write early in the process. We also recommend that you provide your faculty referees with a copy of your completed application and other supporting material.
College of Science Scholarships
Math majors are eligible for many of the scholarships offered by the College of Science. Application information will be mailed to your ONID account in early February for scholarships that begin the next academic year.
Scholarship Information Provided by OSU
This university page contains advice as well as some information about scholarships at the national, state, and university levels.
Some Additional Scholarships for Undergraduates in Mathematics