By raising your hand, you say that you want to tell something. However, raising your hand doesn't say what you want to say.
Raising your hand in itself is already an algorithm. Raisig your hand is followed by a speaking turn.
Change the raising your hand algorithm to a multilink algorithm (other blocks will work too). The student's task is to move the block that corresponds to his will to the front edge of the desk instead of raising a hand.
For example, if the student wants to tell the correct answer, he moves a pink block to the front edge of the desk.
Pink block = I want to answer Yellow block = I want to ask something Green block = I agree Red block = I disagree