STEM Activities: Enhance your science curriculum with the STEM Challenges Learning Cards. Second through fifth graders learn about diverse topics surrounding physical, life, earth, and space science with fun facts and hands-on activities. Dimensions: Each activity card measures 7 3/4 inches x 5 1/2 inches, the perfect size for on-the-go learning and easy storage. The divider measures about 7 3/4 inches x 8 inches. What's...