To Keep Only A Tatal Amount, But Not Keeping The Whole Sheet

Hello everyone,
I need to create a workbook, which has 2 sheets A and B. Sheet A is for insert data and sheet B is for the total amount of sheet A.

Every day, I enter a lot of numbers in sheet A and sheet B will show me the total amount of sheet A. I don't need to keep every detail in sheet A, but I have to keep the total amount of that day.

Because I don't need to keep every detail in sheet A, the next day, I open sheet A again and enter new numbers for a new day. The problem is when I enter new numbers, I get only the total amount of the current day in sheet B. I lost the total amount of the last day.

Please dirent me how to keep only the total amount without keeping the related sheet.

(I have tried to enter data for every day in separated sheets, but the problem was the workbook's size is huge ---> It took a long time to open!)

Thank you very much and I look forwards to hearing from you.
Regards,
Peter