It's a typo! The word should be 'to', not 'top': ..'for the teacher to indicate..' It's obvious that the right-hand edge of the writer's finger touched the 'p' after they had typed the letter 'o'. It's an easy mistake to make.

This is just a spelling error, it happens sonetimes 🤭

Top mean the upper part of the thing W can say go from Dow to top It can means the head too

It looks rather like a typo. It must be "to indicate". By the way, I don't agree with this statement in all situations unless error correction is of the essence in the type of activity the learner is doing. Needless to say, a professional teacher should be able to recognize different types of mistakes and distinguish them from each other in order to deal with them properly.