These stacking cups are colorful and fun, and teach basic counting and math concepts. Each cup is numbered on the bottom from 1 to 6 and is volumetrically accurate. Fill cups 1 and 2, for example, and it will equal the volume of cup 3. Perfect for home, classroom, outdoors, or the tub. Color combinations may vary. Made from 100% recycled plastic, no BPA, phthalates or PVC, meets FDA food contact standards, and it's easy to clean and dishwasher safe. 6+ months.