It says right on the sample test that the child will experience questions that they would be better of doing without a calculator. I just told my DD to use her judgement, she is used to not using a calculator. She didn't have any trouble finishing the math questions in the time allowed.
She thought it was entertaining that the kid with the biggest most elaborate calculator was the only child not to finish that section. She claims it was almost 12 inches by 6 inches, she's never seen one so big.

I just gave her a calculator a few days before and let her play around with it.