Use COUNTIF, one of the statistical functions, to count the number of cells that meet a criterion; for example, to count the number of times a particular city appears in a customer list. If you have multiple criteria you can use COUNTIFS.

=COUNTIF(Where do you want to look?, What do you want to look for?)

A data analyst could use this function to check for any cells in a column that are out of an acceptable range. This would be part of the data cleaning process.