I have taken over a new position at work. This person who I replaced had
created a worksheet that calculates revenue recovery for specific units of
time then also calculates the aggregate revenue recovery over a period of
multiples of these specific units of time. Below is an example of this
formula for the individual unit of time and one for the average over multiple
units of time.

individual =1-(+I38/C37)
multiple =1-(SUM(I38:AK38)/SUM(C37:AE37))

My question is what does the 1- at the beinning of each of these formulas
do? Is it a some type of function like the 3 (counts) or the 9 (sums) do in
the below examples? If so what is its function?

=subtotal(3,a2:j2)
=subtotal(9,a2:j2)

Any help would be GREATLY Appreciated.

Thank you,
JWCardington