Hi,
I suppose one of the problems could have been done without a calculator, with simple multiplication , simple addition, & division… I didn’t want to risk it. The second problem definitely needed a calculator unless you are a super math whiz with crazy skills. I could do the subtraction, but not the division in my head. My math skills are quite good, but not that good. Both were standard formulas, which I knew because I studied them just in case. I am glad I did. The formulas didn’t take that long to learn and I know I got both of them right. Well, I guess there’s no way to know that you got it right, but I would be very surprised if I missed them.