To count the number of non-blank cells in a worksheet, you can use the COUNTA function. This function counts the number of cells that are not empty. For example, if you have a list of names in column A and you want to count the number of names that are not blank, you can use the COUNTA function like this:

=COUNTA(A:A)

This will count all the cells in column A that are not empty. If you only want to count the non-blank cells in a certain range, you can specify the range like this:

=COUNTA(A1:A10)

This will count all the cells in the range A1 to A10 that are not empty.