Is it easier to become a primary school teacher than a high school teacher?

I expect it depends what country you are a teacher in, and the age group of the children you like to work with.

I have worked in both Primary School and High School in Australia.

In Primary school you had to have a broad understanding across ALL subjects because as a general rule, Primary Teachers do not specialise.
Primary teachers teach all subjects.

In High School I specialised in Maths and Science.

In Primary School I had a lot more paperwork to do and a lot more preparation.
My programme was huge with yearly and term overviews and Day Plans across 6 subject levels.

In High school often the burden of programming was shared with other colleagues as was report writing.
Paper work was minimal.

In High School I had more non contact time in which to do this, less non contact time in Primary School.

There was perhaps more marking to do in High School.

Then there are the age levels themselves.
I personally enjoyed working with 10 to 12 year olds.

Teenagers present a whole new set of challenges, but is rewarding in watching them grow into responsible young adults.

Easier is a not the correct word. I wouldn't say learning to be a teacher of really young children is easy. I know from my own experience as a parent of a young child (and I volunteered from kindergarten on) that managing a class of young children is hard work and getting their attention to focus on a variety of subjects despite a relatively short attention span makes it HARD work.
I taught college and high school and I loved it -because I was dealing with people who could talk, read (mostly) and write. Often they wanted to be there (though not always) . It was easier explaining homework assignments and telling them what to read than it was teaching children how to spell, add & subtract and how to read.

Yes, in the United States, but not because one discipline is more rigorous than the other. As there are more primary grades and grade schools than there are high schools, there are therefore more employment opportunities at primary grade schools than at high schools. There are other differences as well, but I would say the reason I explained has the most impact

Will you buy a Tesla Model 3?

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