How to do integration using Scheme language?

Can anyone assist me? I need to do integration and am not sure how to. I have a hitch, however, that I should do a loop for a period of time if I am writing Scheme codes. Am I right? or is there a direct function in Scheme to do this?

Thks for any advice

P.S. I am using the header LPC-2148

What Scheme implementation?

Leon