Logitech has a nifty little accessory for the iPad, simply called the Logitech Wired keyboard and this product is up for preorder right now for $59.99. You can get it from here and know that the product was designed with the classroom in mind.
This accessory comes with super fast plug and play wired connection, that allows you to just plug the keyboard connector cable into the iPad and then you already can type on the device. There are two versions of the keyboard, one with 30 pin connector and the other with Lightning. The keyboard is spill resistant and has a key lifespan of over 5 million strokes.
Logitech’s Wired keyboard for iPad has 3 years of limited hardware warranty and in case you’re wondering about weight, it comes in at 344 grams. Its cable length is 40 cm and the whole thing is just 21.32 mm thick. The keyboard has membrane scissor type keys and the key travel is 2.5 mm. The whole thing looks pretty compact and comfy to use.