Easy Scheme Scripts To Write

1) Write me a script that adds two numbers.

2) Write me a script that counts from 10 down to 1.  MUST USE RECURSION OR A LOOP!

3) Write a script using cond that 
	Stop if the number ever reaches 1.
	If even, divide by 2 and try again.  
	If odd, try again on 3n+1.  

4) Given a number 'n', prints out
	20-n spaces, then 2*n '*'s

5) Call the script above with the number 1-15.


6) Find the square root of a number using the Babylonian method.
	See http://en.wikipedia.org/wiki/Methods_of_computing_square_roots