When the teacher has asked the question write or draw your answer above then hold up your device so the teacher can see it.
This is a much better idea than putting your hands up! This way the teacher can see what everyone is thinking rather than just one person.
When you have written down your answer don't hold your device too high. Just rest it on your desk facing the teacher. We must think of safety first and not risk damaging this iPad/laptop/slate!
Information for the teacher: Here are some suggested activities for which these mini whiteboards can be used:
The image below is from a book published in 1821 detailing how to run a school ('The Lancasterian system of education, with improvements by its founder Joseph Lancaster, of the Lancasterian Institute'.)