Have TurboTax calculate a "total" cell in my worksheet

[joe002]

Instead of using a calculator for multiple entries, I would like to enter the multiple entries into a pop up spreadsheet and have it fill in the total. For example, in  "Total Donation Amount" I would like to hit a button and have it pop up a small spreadsheet where I could add a not and vault for the 4 or 5 items then save it and it would fill in the amount.

I know this feature was available in the past, but I can't remember the key to hit to make this happen.