"I have a big plantation and keep cows and sheep."
I'm a farmer.
"I put down fires and other emergencies".
I'm a firefighter.
What's he going to be when he grows up?
He's going to be a journalist / reporter
"I answer the phone, send e-mails and do other things, all in an office".
I'm an office worker.
What are they going to become when they grow up?
They're going to become nurses.
"I keep and check the financial records in a business."
I'm an accountant.
What are they going to be when they grow up?
They're going to be lawyers.
What are you going to be when you grow up?
I'm going to be a teacher.
What's she going to be when she grows up?
She's going to be a chef
"I build things using the machines at a factory"
I'm a factory worker.