how many tubes of wall paper would i need for a 10 x 10 room 1wall is10 feet long from left to right and 8 feet high from floor to ceiling ?

10 percent more than the total square surface to be covered is standard.  the sq foot coverage per roll is on the wrapper

The vital bit of information is the pattern repeat - you can't just carry on to the next piece - a large repeat can be wasteful. Most designs will quote that and you need to factor it in. Also check you are getting your wallpaper from the same batch number - a different print run can be noticeable half way across a wall, less so if the switch occurs in a corner.

The other answer gives great detail - so I won't repeat the math.

I would like to point out that many styles of wall paper have a repeating pattern.  When lining up the next piece of paper, you want to try to match up the pattern which can often cause some wasted paper.  

How much paper is wasted depends on exactly how often the pattern on the paper repeats.  Plain colors or vertical strips have no pattern to repeat.  Anything with an image or printed pattern is likely to have matching points and the label on the wall paper should list how many inches apart the repeat in pattern is.  The bigger the number, the more paper you might waste just trying to match up the pattern.

You might end up needing an extra roll just because of matching the pattern.

Also, when doing wallpaper, there is usually a lot or batch number on the paper.  You want to try to buy all your paper from the same batch or lot number.  If you buy paper from two different batches, there MIGHT be a slight shade difference in the colors that was used to print the paper.  New batches indicate that a new run was started - which means there could be minor differences in colors.   Many times, it won't be noticeable, but sometimes it is.  

8 feet = 96 inches; 10 feet = 120 inches

394 inches = One Roll length; 18 inches = One Roll width

Q:  How many passes do you need to cover 10 feet?

A:  120 / 18 = 6.67 vertical passes per wall. 

For all 4 walls, you need 6.67 * 4 = 26.67 vertical passes. 

Q: How many top to bottom passes can you get out of 1 roll?

A: 394 / 96 = 4.1  

To get 26.67 vertical passes, you need 26.67 / 4.1 = 6.5 rolls of paper.

Of course, given rooms usually have doors and windows, you may be able to get away with 6 rolls total.  

Your example has non-standard roll sizes.  There are websites which will calculate this for you with more standard sized rolls.