put (one's) hand up
To raise one's hand to indicate that one agrees, wants to answer or ask a question, intends to participate, or wants what is being offered. Don't yell out your questions, kids—put your hands up! I do raise put my hand up in class, Mom, but the teacher never calls on me! Everyone who wants to come, put your hands up now.
put one's hand up
to raise one's hand to get attention from whomever is in charge. The student put his hand up to ask a question of the teacher. She put up her hand to ask a question.
put your hands up
raise your hands in surrender or to signify assent or participation.