this calculator will open port 3000 using sinatra and listen on two

paths the root (http://localhost:3000/) to load the calculator HTML

and /calc path (http://localhost:3000/calc) to evaluate expression

when you write any expression such as (2+2) javascrip will send the

expression as you type to /calc path and get teh result into a div with

id=result

i included the Math module so you can use cos, sin, tan and any method

within the ruby Math Module.

also as this calculator uses eval method you can use it to evaluate a

pure ruby expression such as "Emad "*10 this will print "Emad" 10 times

have fun and let me know how did you use it ;)