count numbers of entries according to parts of string

If you would like to count the entries in an area containing text-values according to parts of these entries you can use the following schema:

{SUM(--(LEFT($A$1:$A$15,3)="ABC")}

explanation:

• $A$1:$A$15 - area to be examined - contains the strings
• LEFT($A$1:$A$15,3)="ABC" - checks the first three letters of each cell matching "ABC"- delivers an array of boolean values (TRUE, FALSE, ...)
  
• --( ) - converts boolean values in binary values TRUE=1; FALSE=0
• {} - Array-Function (needs to be entered using CRL-SHIFT-ENTER)

Have phun playing with it...