Example:   

step 1.Carpet Area  Slider ( 100,500,1000,1500,2000)   <= User Select   ..... Working

Step 2. Salesiq get this selected value i.e 1000

            now i want to internally salesiq multiply with 3 (1000*3) and return result 3000 to user 

step3. Your Total area will be 3000

Problem : where this 1000 get stored and how to calculate 1000*3 and from where to get result

Note: I have provided screenshot and code of given problem below..