How Many Decimal Places?

It is becoming a real pain in the butt coming up with different answers than the EOC Q’s due to rounding, especially when I’m trying to construct a table going out a few years. Anyone got any advice on how many decimal places to round to on these exercises? For the most part it won’t matter, but some test answers are close enough to each other to where the rounding does matter (i.e. the value of a contract after inception). Thanks.

Majority of the problems use 4 decimal places. May have to switch to 6 for some FX material.