But they're so expensive and small compared to a blackboard. Another commenter got a 4 foot x 6 foot blackboard, it was probably a few hundred dollars (plus the

But they're so expensive and small compared to a blackboard. Another commenter got a 4 foot x 6 foot blackboard, it was probably a few hundred dollars (plus the cost of chalk) and will last for decades. A 50' Microsoft Surface Hub, that's ~2 1/3 foot x ~3 1/2 foot, is ~$9,000 and will be lucky if it lasts 10 years. There are cheaper large touchscreens but they won't use capacitive sensing which is what makes the Microsoft Surface "snappy."