During our courses, we found that some of the participants are not very sure when to use SUM and COUNT. A few of them have the impression that when you need to total up the numbers, e.g. number of employees, COUNT should be used. This is not always the case. The rule is to remember that when you need to count the number of cells in a range, you use COUNT. Therefore, if you select 2 cells, the COUNT result is 2. If the numbers in the 2 cells are 9 and 8 respectively, SUM will give you the result as 17. The same concept applies to SUMIF and COUNTIF.