Memorize Formulas?

Is it critical to know how to do the formulas by hand? I can do a lot of the questions on my calculator, but I can’t spit up the formula on command. Do you have to do that on the exam?

if you can do it on your calculator, dont worry about it. know what formulas mean, which factors move certain things up and down, etc but actually going in and discounting all bond cash flows when you can do it on a calc is a waste of time.