How to set the calculation values for the dropdown field of an Input Table?

I need to add calculation field in the form which I am unable to do, I looked up the help from https://www.jotform.com/help/343-How-to-Perform-Form-Calculation-in-the-Matrix-Field as well however I am still not able to do so.

You simply need to click on the "Add Form Element" tab, then click on "Widgets", and look for the Form Calculation field, example:

Let us know if you need more help.

I am unable to understand how to put calculation there, I am unable to calculate or put calculations there.

As far as I understood your idea when checking the form you shared, it seems that you're trying to assign calculation values to a dropdown choice of the Input table. 

Please note, that when setting the values you must separate the columns with comma, but I can see just 1 column at your Input table:

I've made some tests, but unfortunately could not find a way to assign calculation values to a dropdown field of the Input table.

Summing up, I can suggest to split the dropdown choices into 3 columns named "Yes", "No", "NA". You'll be able to set the calculation values afterwards as "2, 1, 0" for every row:

Here is the test form:

https://form.jotform.com/80716083283962

Please feel free to clone it:

How-to-Clone-an-Existing-Form-from-a-URL

If you need more help with your JotForms, just let us know.