The D.C. Black Memorabilia and Collectible Show features exhibitors selling and showcasing historical artifacts, toys, autographs, art, postcards, political memorabilia, a collection of slavery artifacts and much more. 10 a.m.-7 p.m. Saturday. Montgomery County Fairgrounds, 15 Chestnut St., Gaithersburg. $5; free for children 12 or younger. 301-216-0876 or www.johnsonshows.com.
TONGUE & GROOVE
Class Acts Kaleidoscope Performance Series presents the company Tongue & Groove, performing step dancing, American clogging, tap dancing and body percussion, with a live band. 4 p.m. Saturday. National Oceanic and Atmospheric Administration auditorium, 1301 East West Hwy., Silver Spring. $6 in advance, $8 at the door. 301-588-4475 or www.classactsarts.org.
The Germantown Community Center will host KidsFest, featuring interactive recreational activities for youth, including a giant firetruck slide, moon bounce, arts and crafts, face painting and a toddler play area. Activities by the national program Hearts N' Parks, which educates communities in healthy lifestyles, include a diaper derby, stroller races, football toss, home run derby, karate and bowling. 3 p.m. Saturday. Germantown Community Center, 18905 Kingsview Rd., Germantown. Free. 240-777-2474.