Yes. Better if you CAN total but, if you’re running out of time, then just the “line workings” will do. I presume that you’re talking about things like adding up the inventory as (for example) 30,000 + 42,000 – 3,000 (pup)
Yes, that’s fine
Ask yourself this question – what is the exam testing? Is it my ability to add up? Or, more likely, is it to test my understanding of the principles involved in producing a Consolidated Financial Statement?