Many classroom products (such as pens, pencils, and glue sticks) include caps. Some of these caps serve multiple purposes. For example, certain glue sticks have caps that not only to protect the glue from being exposed to the environment, but also have additional uses, such as cutting, pasting, and taping. There are also many toy products on the market designed to interact with moldable substances, such as Play-Doh®. These include blocks and stamps that feature all sorts of playful structures and shapes. None of the abovementioned products, however, are versatile enough for use as teaching/learning aids in classrooms. More specifically, none of these products have caps that allow multiple products to interconnect with one another, which can be useful in creating educational designs, patterns, or demonstrations. Such caps can bring added-value to the classrooms and environments in which these products are often found (sometimes in multiple quantities both during and after their immediate use). There is thus an ongoing need for items that can be used multiple times