Problem: How to calculate an average but exclude all zero values?

Solution:

=AVERAGE(IF(A1:A10<>0,A1:A10,FALSE)) + Ctrl + Shift + Enter

AVERAGE(number1;[number2},...)
Returns the average (arithmetic mean) of its arguments, which can be numbers or names, arrays, or references that contain numbers.

IF(logical_test;[value_if:true];[value_if_false])
Checks whether a condition is met, and returns one value if TRUE, and another value if FALSE