Excel formulas that will find the average of cells A1, A2, and A4 are:
=AVERAGE(A1 ,A2, A4)
or
=AVERAGE(A1:A2, A4)
=a1+a2+a3
The "Sum" formula works best.
The values in cells A2, A3 & A4 will be added together - and the result displayed in the cell that contains the 'sum' formula.
The equals sign. =SUM(B1:B7)
=SUM(D7:E20)
The sum of 7 and 4 is 11, whether in an Excel spreadsheet or anywhere else. In Excel the formula would be =SUM(4,7) or =4+7 or =(B12+B13) if the values 7 and 4 were in cells B12 and B13.
In another cell, you would type in =SUM(E1:E11)
I need more detail in order to fully answer your question. Are you sure the sum formula includes the cells that you are changing?
To sum a range use the formula =Sum(first cell:last cell) So in the exaple you give it would be =SUM(B8:B11)
Since you put this question in the Excel category, I will respond with an Excel formula. Assuming you put your numbers in cells A1 through A100, the formula would be:=SUM(A1:A100)/100
Equations perform some type of operation.EXAMPLE:Find the sum of all numbers in the cells A1 through A23.The formula is =SUM(A1:A23)
=SUM(C5:C18) will add the values in all the cells from C5 to C18 and put the total in C19 when the formula is placed there.
If you have numbers in cells B1 through B134, use the formula: =SUM(B1:B134). You can use auto sum to insert the formula by highlighting the column (you can click on the column letter) and clicking the AutoSum button on the menu.