Mr. and Mrs. Rick Tobin of Woonsocket, S. D., along with Jim and Gay Pearson, Brooklyn, announce the engagement of their children, Cassie Jo Tobin and Rick Lee Pearson. The bride-to-be is a 2007 graduate of Dakota State University, Madison, S.D., with degrees in elementary and special education. She is a second grade teacher in Chamberlain, S. D. The future groom is a 2008 graduate of Winona State University, Winona, Minn., with a degree in physical and health education.