Reference Cell & Add Amount If Positive & Subtract Amount If Negative

Im trying to set up an active running inventory sheet where: (A)the progressive daily sheet cells reference back to the corresponding master sheet cells fluctuating the master values, (B) the same progressive daily sheet cells reference back to a cummulative totals-cell based on whether I added or subtracted inventory. I want to make a copy of the blank "sheet 2" with all of the formulas and move it to the end of the workbook each day and enter new values which will reference back to the master sheet so that I can click on a date sheet and see an individual day's values or click on the master sheet to see the fluctuating inventory on-hand and the cummulative +/- totals of all days combined. I've got a couple hundred individual cells to reference. I've tried and tried but I can't make it work. Heres what I need to do:

I need to reference individual cells from "sheet 2,3,etc" back to a corresponding cell in a master sheet. But I need the values in each cell in "sheet 2,3,ETC" to increase or decrease the corresponding cell values in the master sheet. For example: If the value in the master sheet B5 is 200. Then in sheet 2, I enter +50 in B5, I need the master sheet cell B5 to increase by 50 to 250. I also need a way to decrease the cell value in the master sheet B5 if I enter a negative value -50 in sheet 2 B5. I also want to know if I can reference the same cell values entered in "sheet 2,3,etc cell B5" back to totals columns C5 for adding inventory or D5 for subtracting inventory in the master sheet where the master totals columns would reflect cummulative totals added or subtracted. For example: if the value in sheet 2 B5 is +50, then the value in Master sheet C5 would add 50 to a progressive total. But if the value in sheet 2 B5 is -50 then the value in master sheet D5 would add -50 to a progressive total.