Engneering 2
"How many digits should I keep in my final answer?" Keep as many digits as possible during the calculations. At the end, round to 3 digits. This will always ensure that your rounded answer is within 1% of the exact answer, which is good enough for this class.
"When should I use an Engineering Prefix?" Everyone has a different preference, but I usually use an Engineering Prefix for numbers greater than 1000 (kilo, mega, giga, etc.) and for numbers less than 0.1 (milli, micro, nano, etc.). For numbers between 0.1 and 1000, I typically do not use an Engineering Prefix.
Example: 567 Ohms. 567 is between 0.1 and 1000 so I would keep it as 567 Ohms.
Example: 1023 Volts. 1023 is greater than 1000 so I'd use 1.023 kV (kilo Volts)
Example: 0.056 Amps. 0.056 is less than 0.1 so I'd use 56 mA (milli Amps)