How to Sum value from current cell plus input cell - excel

Question

I have two problems:
How to make a cell input? I need to enter a number and after pressing "enter" delete the number so I can add more input.
How to SUM the entered input with the value of another cell, for example C3 and store the result on C3?
I don't know how to delete the cell after pressing enter.
I've tried writing at C3 "=SUM(C3+F3)" and "=0+SUM(C3+F3)" both gave me a #REF ERROR.
Case:
I want to know how much money I have spent in one day. So C3 cell at the beginning have a 0 and F3 cell (input) is empty.
The point is if I buy a $3 souvenir, write 3 at F3, press enter (delete the 3 to make F3 empty) and make a SUM with whatever was at C3 plus that $3.

Answer 1

I would create a button, then it is clearer what you want to happen, though you could hook into the key press.
Go to File Options Customise and customise the ribbon to add the Developer tool bar.
on the Insert command, add a new button to the form. It will ask which macro you want, click New
Past this code:
Sub Button1_Click()
Range("F3").Value = Range("F3").Value + Range("C3").Value
Range("C3").Value = ""
End Sub
into the button click, and then when you click the button it will take the value in C3 and add it to F3 and then clear the value in C3.
Remember to save the workbook as MACRO ENABLE WORKBOOK, else the macros won't save.
click button
Hope that helps

Answer 2

Overwriting the same cell with different values and then expecting a sum of the previously entered values is not a good approach. If you want to understand why the result is a specific value, you need to be able to see which values contributed in which way to that result.
The better approach is to list all different numbers in one column and then calculate a running total in another column. Just like a bank statement. A bank statement shows you the current balance, but also each transaction, debit or credit, that went into calculating that balance. If you did not see the transactions, you don't really know if your pay check has already been included in the balance or not.
If you overwrite the same cell multiple times, how do you know if you have made a mistake and entered the cost for lunch twice, or made a typo in the numbers?
So, enter the data in rows. Each data point in a new row. Maybe use a column for date, one for money spent. Then use simple formulas in other columns to calculate what you want to calculate. You won't need any VBA or script or buttons for that.