Fraction multiplication is actually much easier than decimal multiplication imo. I'm surprised so many people seem to avoid it. Keeping track of where the decimal point should be is a significant cognitive load.
This is nearly a tautology. Economic engagement with the rest of the world is obviously good for any single country (especially when you're essentially cherrypicking the rules you follow while the rest of the world is mostly compliant). But if that country is poised to become the next superpower and its leaders are the modern day analogue of imperial Japan or the USSR, that economic engagement is probably not good for the rest of the world (in the long-term).
So n miles = 8n / 5 km
And m km = 5m / 8 miles
Fraction multiplication is actually much easier than decimal multiplication imo. I'm surprised so many people seem to avoid it. Keeping track of where the decimal point should be is a significant cognitive load.