There are two testing systems (CATS and Lasergrade), so there might be some variances in what each system provides. I took mine on CATS, and I believe there was a simple math calculator available as a pop up but without aviation functions it's not really useful.

However, my recommendation is to buy an FAA testing-approved calculator with all the aviation functions. If you're like me you use a smartphone for all flying ops - which isn't allowed. So buy it from Amazon, practice with it while prepping, use it on the test, then return it when done since you likely have a good calculator on your phone. Simple.

I tested under the old system and used Sheppard Air so think I broke out the calculator only once or twice. With their gouge you likely know most of the math answers ahead of time.