as days pass by

OK, if you know anything about maths you will read this and shake your head in dismay because it's just obvious and why did I even need to think about it? But... I was quite pleased to think this through, so I thought I'd write it down in case anybody else finds it useful. So. Your job is to calculate the average of a set of numbers. This is not hard: the average value1 is the sum of the numbers divided by the count of the numbers. So the average of 2, 7, 8 is 2+7+8 17 ----- = -- = 5.666… ...