Answer:
When a teacher asks you this you need to come forward and tell the truth. Teachers want to help you as much as they can. You can:
a) talk to them after class
b) ask to meet with them during study hall of lunch
If you don't want help from your teacher, ask for help from a peer. They will help if they understand.
Once I was having a really tough time in Algebra. I was almost failing. I went too my teacher and asked him for help. Willingly, he made an hour of his time into a meeting to help me boost my grade and understand,
The key is to come forward and tell the truth and ask for help.