Earlier quoted context omitted.
It's going to depend based on context. In this case, context was unclear and a misunderstanding ensued. I have nothing to back this up except experience, but I think the thumb up is less common is Europe than in the US. In this specific case, I think the expected answer is to confirm the number by flashing the same sign. A nod would also work, but be potentially less clear/easier to be missed. The ok gesture would li…
The ok sign usually means zero in France. In this situation; as a Frenchy; I would have repeated the count to confirm while nodding. Or waved my hand while shaking my head to refuse.
We may use the OK sign to signify 'au poil' (very fine) most often with pinched lips (mock Italian face).