Select the cell where you want the average to appear
Type `=AVERAGE(`
Select the range of cells you want to average
Type `)`
Press Enter
Use `=AVERAGE(A1:A10)` for a simple range
Use `=AVERAGE(A1,A3,A5)` for non-adjacent cells
Use `=AVERAGEIF(range, criteria, [average_range])` for conditional averages
Use `=AVERAGEIFS(average_range, criteria_range1, criteria1, [criteria_range2, criteria2])` for multiple conditions