The Appendix that will be attached to the exam paper can be seen here
Overview of approved calculators: /studier/eksamen/hjelpemiddel/mn-math-kalkulatorer.html
The paper that you write on consists of several layers (to make copies for the external examinator), so write with a pen, and don't use a corrector pen. If you make a mistake, cross over the mistake (or take a new sheet of paper) and write again.