first the author calculates the parallel resistor's resistance and combines them to get a single resistor to make it a series circuit. the total resistance for the first one is 71.42857142857143 but he just shortens it to 71.429 then later on when he finds the voltage drops the first one is 8.6275591343733427 but he writes it as 8.6275 instead.

my question is why does he sometimes write it with 2 numbers after the decimal point and sometimes more. It might seem like a dumb question but when i calculated the current for the first parallel circuit with 8.6275 it came as 34.51mA but when i did it with shorter number 8.63 the answer came to be 35.52mA. if i were to use the shorter number then the result would of been different

**So my question is when should i round down the number to 2 decimal places and when should i round it to more than 2 decimal places?**i have included a link at the bottom to the text in case you would want to see for yourself

https://www.allaboutcircuits.com/textbook/direct-current/chpt-7/analysis-technique/