I've had a personal experience with people (not developers) who couldn't understand the concept of simplifying equations. So it was "add 20%, +8, x 2," or something to that effect. I said "you mean x 2.4 + 16". Their response was "just do what we said." So I think a minimum level of math is required, just like a minimum level of language skills.
Would the code for the simplified equation be commented so that a business type who wondered why it was represented that way would understand what underlying expression went into the code?
I heard a scary story from a professor of economics who teaches business students. She said she talked about multiplying some value by 20 percent, and wrote on the blackboard "* .2," and then had students ask her why she wrote ".2" on the board when she had just said "20 percent." It probably avoids business logic mistakes to make the steps VERY explicit, so that the businessperson doesn't try to "correct" some error in the formula.
I remember working in a bank and a colleague having to explain operator precedence (multiplication over addition) to a "programmer" who did not understand why his program did not work. Scary to think about people like that writing software to handle people's money.
"Would the code for the simplified equation be commented so that a business type who wondered why it was represented that way would understand what underlying expression went into the code?"
Why would a "business type" be looking at raw source code? (unless maybe said code is in COBOL)? I am not being sarcastic, but I've found even good business folks, being lost in (what to my eyes was) very clean code.
I was wondering if it might be useful for subsequent programmer to be explain on the spot (as, for example, in an IM conversation--thanks for that follow-up) that the code is indeed doing what is desired by the business logic.
