Not being funny but that's one of the most complex 'simple' processes I've ever heard of.
So let me see if I've got this straight.
Firstly, I need to have a bit of familiarity with my 12x table beyond the standard 12 12s. Great, well done. Brilliant. So simple. I'll just divide 168 by 12. Super easy. I LOVE having to think very carefully when I just want a sausage roll.
I've then got to remultiply this by the carb count on the packet and then divide by 100. Incidentally, your 'simple' system of rounding down could put you out by as much as 5-10 carbs, which can be the difference between needing an extra unit of insulin, or not
Yes, I know how to calculate the amount of carbs in a product through maths. The whole point (which you appear to have missed) is that if they're already putting on a load of 'per portion' nutritional information on the pack anyway, why not put the carb count as well. That way, I wouldn't need to get out a calculator every time I want something to snack on. You know, make my life easier and all? Once again....if a manufacturer is going to go to the effort of calculating and printing the completely useless 'sugars' figure per portion, why can't they just put a useful measurement on there as well?
Costing ?1.70 and weighing 168 g it's ?10 per kilogram - looks like expensive processed food to me. And then there's the question of horse and donkey meat, especially with the chorizo.
Relevance to the point of having easy to use nutritional information on the packet? Sorry if I didn't cite an example that was more in keeping with your personal budgetary agenda.