The latter of the two options above - no need to define each variable in the formula. The formulas are well-known in the CFAI cirriculum so I don’t think there’s a need to spend unnecessary time defining all variables / inputs.
May even necessary to get full credit. If you write down the symbols, the grader knows that you know the formula. Otherwise you could just add up some of the given numbers and hope it’s right. Therefore, always write down the formulas and in case you use any symbols that are not cfa standard, shortly say what it is. The same if you use formulas in another format than in the books…
This is bad advice. Think about it. If you got marks for randomly adding up numbers from the question, you’d get the same marks if you just wrote down their names before you plugged it in.
i have always been told (and even LevelUp Bootcamp participants can attest to it) write the formula, plug the numbers, show final calculation.
that way - during the plugging of the numbers into the calculator, or even if you wrote a wrong number somewhere - you get some partial credit, as opposed to you writing a stream of numbers - and no one knowing what number stood for which symbol.
give the graders something to hang the grade on.
and believe me you will have few questions (a handful at best) where you have to “Show calculations”.