How to embed a very simple spreadsheet on the form

Dear JotForm,

I am considering upgrading our account, but I'm having one sticking point. I want to embed a very simple spreadsheet into the form and have users input numbers - this is for a projected project budget. I only need one column of the spreadsheet to total. But this seems completely impossible. I've spent two hours now trying to figure out how to do this, but your spreadsheet widget is wonky and the form calculation function has everything other than simple addition!

This seems like a no brainer, and maybe I'm the one with no brain. I just couldn't figure out how to do it. Like I said, I'm considering upgrade but this is a non-starter.

Thank you!

How about using the Spreadsheet widget. It will allow you to add a spreadsheet on the form itself. 

link: https://widgets.jotform.com/widget/spreadsheet

Please check the demo form also https://form.jotform.com/61441655557965

Let us know if you need further assistance.

I did try the spreadsheet widget! What do you think I was talking about?
This is not useful.

...

If I understood you correctly, you are not able to perform a calculation inside of the Spreadsheet widget. I inspected the forms on your account, but I was not able to find a Spreadsheet widget. Please provide us an ID of the form you are working on and tell us in which column you want to perform a calculation. 

You can also clone and inspect the form that my colleague provided you.