I need some help with loop and Streamreader

im using visual basic 2010 and using a streamreader to access a .txt file.
So I want to be able to open a .txtfile and extract certain information from it.

So far example, in the .txtfile it would say:
math
what is 2*3-9?
-3
math
what is 1*2*3?
6
chemistry
what is Ar?
Argon
What is O?
Oxygen

I'm trying to create a streamreader with a Do While Loop. So when I click the "Math" button, a math question would show up the textbox. and the user writes down an answer for that question.