Apparently teachers ask up to two questions every minute, up to 400 in a day, around 70,000 in a year, or around two - three million in the course of a career! Questioning accounts for up to a third of all teaching time, second only to explanation time.
There is also research to show that relatively few teacher questions demand higher order thinking (between 4 - 8%). Lower order questions can create momentum but often merely require pupils to recall information in the form in which it was presented to them.
Research from the United States suggests that at all ages a combination of higher and lower order questions was the most effective method to generate successful learning. A greater proportion of higher order questions (to about 50%) brought significant gains in terms of student attitude and performance.