Finding non-REU funding for my undergrad math students As a professor, I am sometimes asked to help undergrads (I'm currently at the University of Michigan) find funding for math research during the summer. In the past I have seen some get funding from the NSF REU program. The only problem with this is that it is only 8 weeks (At least at my school). Are there any other research grants that are given to undergrads that could last the entire summer?
I'd also ask around your department. Many universities have various summer research fellowships available. For example, one enterprising student in my lab found money through NASA that was administered through the physics department but also funded math, science, engineering, etc.

Also, most funding organizations are happy to "pad" a research grant with 1-2 undergrad research positions. I usually add these to my budget when submitting. While other areas get trimmed, the undergrad positions have never been a problem.