Dominic Rudakevych and Marilyn Fisher, 2014 champions of the National Marbles Championships in Wildwood, N.J., pose at the marbles rings in Middletown, Md. The two 13-year-olds train with the Frederick County Knucklers, a competitive marbles recreational program in Maryland. NPR/Sarah Tilotta hide caption

itoggle caption NPR/Sarah Tilotta

Preschool student Stormy Frazier watches a science experiment unfold in Nikki Jones' classroom in Tulsa, Okla. You can learn more about preschool in Tulsa here. John W. Poole/NPR hide caption

itoggle caption John W. Poole/NPR