Excel

I have twelve monitors, four computers, two mass spectrometers I analyze for twelve hours a day but I can not figure out excel.  All I am trying to do is find the mode function to take six columns of data 1 2 3 4 5 6  mode. that is it.  

Thank you and yes I will put a shoe on my head. I am using windows 10 and my function is in excel.  It should be a, b, c, d, e, f, g which one occurs most frequently = mode.