I thought math was relatively universal. The US education system may be different, but I'm certain we're not the only place that does it that way.

I live in Australia and don’t recall my school at all teaching me this in maths class

I'm in Australia, and I remember being taught it, and I teach it.

people exist that live in other countries and every countries education system is different

The rules are the same everywhere, only the notation varies (in Germany they use . for multiply and : for divide, and say "dot before slash", slash being - and +).