Interactive games are sometimes helpful, especially online, but there’s nothing like holding something in your hand to help you understand it. A great example of this is the quasi-holiday of the 100th Day of School, widely celebrated in elementary classrooms everywhere. It’s fun for kids, but also a great learning tool. One of the more popular activities is for each child to collect 100 items, such as pennies, bits of cereal or candy, sunflower seeds, etc. Seeing, feeling, and touching the number 100 in this way really drives home the concept.