The Catholic Tutor Corps has been placing volunteer tutors in Minneapolis and St. Paul Catholic grade schools for 20 years. These tutors work in grades K-8 helping students primarily with reading and math. They work in the schools during the school day. Most of these tutors work 1-3 hours once a week at the school, though it is certainly possible to work more days if you have the time. The benefit to the students from one-on-one help is huge; the reward to the tutors can be even greater.
Learn more and volunteer by visiting their website: https://catholictutorcorps.com/