It’s the teacher’s birthday, how can we collectively surprise her?

Buy a heart-shaped gift box, give each person a small card, and write the best wishes for her from all your classmates in it. Don't make any noise during class that day. When get out of class is over, stand up and sing Happy Birthday to her. Of course, you can be the lead singer, and then give her the small box and wish her a happy birthday.

What do you think? It doesn't cost much and the effect is good. We did it this way before, and the teacher was very moved.