Often we want to summary the total number of particular value, for example: we want to summary how many students got HD, DN, or CR?
Simply just using formula COUNTIF
= COUNTIF (Range of the data, cell position of value as reference)
= COUNTIF ($A$2;$A$12, I13)
it is said “put value in this cell with the number of values in range $A$2;$A$12 which contains data same with I13”