@Baz posted:Although I spent a good deal of my working life in accounts , I gave up trying trying to understand trig …or algebra …at school….I was useless at it .
One of the clients I had when I was I was an audit manager was a provider of finance to other businesses. The client had lots of subsidiaries with a variety of year ends. One year they changed their accounting system during the course of the year. Then the group year end came. All the subsidiaries had to to accounts to that year end besides their own year end. It was at that point in time when the client discovered that due to the change of the accounting system, the subsidiaries were unable to generate the figures necessary to get accounts for the group year end. Their own year end weren't a problem.
The clients accountants tried to see if they could work out how to generate the figures needed but couldn't.
I got to hear about this one Friday afternoon. I got the client to give me some specimen reports to see if I could work out how to generate the needed figures over the weekend. I succeeded and on the following Monday morning I gave the client the way to work the figures out.
It was an algebraic formula with say a dozen variables. The only time in my accountancy career where algebra was really useful 
(after I was made redundant and became self employed I would go to that client to help in their year end accounts work, I earned quite a lot of money for a few years and that was their way of thanking me for saving them)