I am going to London to study, and I have been looking at the prices of the popular things to do, and compared to the US dollar it seems frightfully expensive.Can anyone recommend something cheap,fun, places I should see and shop that won't make me have to drop out of school? Thanks!

Many of the museums are free.

Don't shop. Actually supermarket prices are broadly comparable, if you shop in proper supermarkets and remember that British supermarkets' own brands are far superior to their US equivalent. As a general rule, only the terminally gullible buy manufacturers' brands here.

You won't find your fellow students have a great deal less fun than their US equivalents. So just do as they do.

As flanneruk suggests, ask your fellow students.

frequently on certain days things are open for free....students get a significantly reduced price at almost every location and at the theatre...

For theatres, seats with partially obscured views or standing are often quite a bit cheaper than other seats. Preview shows are also cheaper. I never felt that my view was ruined in the supposedly bad seats.