How much am I going to earn?
You need to have an idea how much you are going to earn this year before taxes. 

You start your student job in March, which means there is 10 months left of the year. You earn DKK 4,500 a month.


DKK 4,500 x 10 months = DKK 45,000.

You write DKK 45,000 in field 201.

If you have had an income from another job before you started your student job you have to add that amount to the 45,000 kr.