Syntax:
SUM(Number1 [, Number2, Number3 ...])
Description:
This returns the sum of the given numbers.
Number1, Number2, etc., are single values, cell ranges or arrays that contain the values to be summed.
If you use this function with cell references (for example A1:A3), only numbers are considered, while text strings and logical values occurring in the referenced cells are ignored.
However, the situation is different if you type fixed values directly into the formula: Here, numbers entered as a text string (for example, "42") are included. Furthermore, the logical value TRUE is treated as 1 and FALSE as 0. See examples below.
Example:
SUM(1, 2, 3, 4) equals 1+2+3+4, which is 10
If the cells A1:A4 contain the values 1, 2, 3 and 4, the following applies:
SUM(A1:A4) equals 1+2+3+4, which is 10
Please note:
If the cells A1:A3 contain 1, "2" and TRUE:
SUM(A1:A3) returns 1, since the text string and the logical value are ignored.
They are counted only if they were typed as fixed values directly into the formula:
SUM(1, "2", TRUE) returns 1+2+1, which is 4
Additional info:
There are some special terms for the SUM formula, where PlanMaker automatically completes the formula with additional functions. The following examples illustrate how it works:
If you enter SUM(A5:A), all values in column A are added, except A1:A4.
If you enter SUM(E2:2), all values in row 2 are added, except A2:D2.
If you enter SUM(A:A10), all values of A1:A10 are added.
If you enter SUM(2:E2), all values of A2:E2 are added.
You can also use the AutoSum icon 
on the ribbon tab Home | group Contents to quickly calculate the sum of a specific cell range:
Select an empty cell just below a group of cells containing numbers and then click on the AutoSum icon. The Sum function for the cell range above is now automatically inserted into the selected cell. You just have to press the Enter key↵ to display the result.
Alternative method: Select a range of cells with numbers and then click on the AutoSum icon, which will insert the sum of this cell range just below these cells.
You can also apply the AutoSum icon for several other arithmetic functions. To do so, click on the arrow to the right of the icon. PlanMaker will open a dropdown list containing the available functions – for example, Count, Product, Average, etc. Select the desired function from the list to apply it to a cell range using the methods just described.
Note: The last selected function from the list will be applied again when you click directly on the AutoSum icon.
See also:
PRODUCT, SUMPRODUCT, SUMIF, SUMIFS, SUMXMY2, SUMX2MY2, SUMX2PY2