You don’t have to be Irish to participate in these celebrations. (St. Paul: Noon March 17. Along 5th St. from Rice Park to Mears Park. stpatsmn.org. Minneapolis:6 p.m. March 17. Nicollet Mall, Mpls. mplsstpats.org) You don’t have to be a whiz at algebra to celebrate this mathematical holiday. Participate in games, math puzzles, food, a raffle and more. (5:30-8 p.m. Fri. Mathnasium, 4785 Cty. …