Carthage was Rome's main rival in the third century BCE. The Carthaginians were able merchants, wealthy, well-connected, knowledgeable, and they had a strong land and sea military. Definitely trouble for Rome, and not that far away.
When Rome defeated Carthage in the Second Punic War, it cleared the way for Rome to dominate the trade of the western Mediterranean. And since the Greek states seemed intent on destroying each other (and Athens itself from within), this really allowed Rome a safe neighborhood in which to become dominant.
True, post WW2 Japans economy boomed and especially in that time they became a world economic power and today they are still one of the strongest economies in Asia.
The word calculus comes from Latin (Calculus) and refers to a small stone used for counting
