It’s how CPUs do floating point calculations. It’s not just javascript. Long story short, a float is stored in the format of one bit for the +/-, some bits for a base value (mantissa), and some bits for the exponent. As a result, some numbers aren’t quite representable exactly.
How do people in Japan think that 10% of the population is foreign!?
I guess Argentina makes a bit more sense - except that not many people are trying to get to Argentina. That sounds like Argentina though.