When to use rules of significant digits vs when to avoid dilution of precision

Question

I’m confused as to how, when and why I’m supposed to use significant digits vs when to carry all the decimals my calculator spits out. This is for surveying/civil engineering related fields in particular. My professor has covered both topics extensively but didn’t do a very good job explaining when said rules apply.

In: 0

Answer 1

You use all the decimal places the calculator gives you while you’re doing the calculation. You only round to however many significant figures when you’re giving your final answer. You want the most accurate answer possible, and rounding too early can change your answer.