Hello

I've been tasked with creating a spreadsheet that records the monthly
electricity meter readings where I work.

It's a big site with aboout 20 different meters to read around the site once
a month.
(The meters measure Kilo-Watt Hours) KWH
Some of the meters go right around the dials more than once so if say the
meter read 61567 one month, then the next month it could read 00123.
I can't then just subtract past reading from present reading because it
won't reflect the number of KWH used.
Each dial counts 0 to 9 for each digit.

The true KWH used in this example would be 00000-61567 = 38433 then
38433+00123 = 38556 KWH
It would not be 00123-38433 = -61444 KWH

From each meter reading I need to work out the total KWH used each month.

How do I go about creating a spreadsheet that the user can enter this months
figures (present) and last months figures which were then present now become
past figures so I can do the calculation.

I need to be able to use last months figures and this months figures on a
monthly basis to do the calculations.

Sorry it's long and confusing !!!

Any help much appreciated

Thank You