The word is nurse. A nurse is a person who is trained to take care of sick people.
There have been people in Australia for tens of thousands of years. No one knows the name of the very first person in Australia.
It is impossible to tell, but is probably in the tens to hundreds of thousands.
Tens
A lighthouse keeper.
30 tens does not equal 3000.
It is difficult to provide an exact number, but Phoebe is a relatively uncommon name. It is estimated that there are tens of thousands of people named Phoebe worldwide.
There are tens of stadiums.
From the beginning of the human race, many tens of thousands of years ago, whenever people have been sick or injured, somebody has had ideas on how to cure them. This gradually coalesced into the idea of a particular set of people with the task or profession of curing, and formal qualifications needed to belong to that set of people.
tens
tens of millions
it means to estimate a number by tens
tens