The presentation of the answer in the exam

Hello! I have some general question regarding the presentation of my answers. How it is important to give some standard presentation in answers at the real exam? I practice different Exercises, than check my work and see that I calculated correct, however it is done in a little bit another way, but the final answer is the same. For example, in the question about opportunities cost, the answer provide the scenario of calculating of contribution per unit, than the difference in contribution and how much profit would be lost, I calculated "old" and "new" revenue, cost, profit and this difference. The result is the same, but presentation is not. Should I do comment as much as possible if I am not sure standard structure I use or not? Will be it enough? Thanks in advance! Best regard, Victoria