Grades K & up. Keep it simple with real STEM learning! Discover amazing engineering wonders through scientific exploration with colorful, engaging tools and hands-on activities and experiments. Introduce and explore all 6 simple machines as you make amazing discoveries, design solutions for real-world problems, and conduct your own investigations. Comprehensive activity guide with reproducible materials is also included. Largest piece (cart) measures 5"L x 3 1/2"W.