Use the FREQUENCY function to count the instances a particular number occurs in a series of values. The function requires a set of ranges (or bins) to group the values. For example, use bins of 5, 10, 15, and 20 to report the frequency of values in the ranges 0:5, 6:10, 11:15, and 16:20. Because FREQUENCY is an array function, you must first select a range of cells the same size as the bin range, then type the function =FREQUENCY (A1:D15, F2:F5) then press Ctrl-Shift-Enter. This example uses bins in the range F2:F5 to count numbers in the range A1:D15.