Round and Round

"Secrets of Circles" allows children ages 3-10 to climb into a circular boat, play and pretend as they explore the math, science and engineering of this common shape. Visitors will get firsthand experience with circle-related technologies, including pulleys, gears and measuring devices. (9 a.m.-5 p.m. today; 9 a.m.-4 p.m. Tue.-Thu.; 9 a.m.-8 p.m. Fri.-Sat. $9.50. Minnesota Children's Museum, 10 W. 7th St., St. Paul. www.mcm.org.)

MIDWEST BLACK HISTORY EXPO

For the first time in the Twin Cities, Black History Month is going from the classroom to RiverCentre. This event welcomes all to learn about black inventors and inventions, history and more. A children's room features storytelling and activities. See films by black filmmakers and enjoy live entertainment and fashion shows. (10 a.m.-7 p.m. Sat. $13. St. Paul RiverCentre, 175 W. Kellogg Blvd., St. Paul. 651-265-4800. www.liberationgifts.com/expodetails.html.)

Melissa Walker