Iida knew you could be really bad at math, but she never imagined that Aizawa would ask him to help you, so as your class representative he didn't refuse

"Very well... You did this exercise very well... But now I'll explain this one to you..."

Iida began to explain a math subject to you, one that you didn't understand at all but struggled to understand even though you were nervous about Esther around him, because of your secret crush on him.