jus as de title.... how to reduce de difference in therotical value and measured values of resistance measured by a multimeter???

 

Any given multimeter will have an error characteristic about which you can typically do nothing. There may be instuments for which calibration is possible. If so you should have the instrument calibrated. Any given resistor will have a value given by a distribution with a mean and a variance. The only way to get more precise measurements is to use better equipment.

 

Look at the specifications of your multimeter.

Your meter can introduce a lower load into your circuit, throwing the readings off.

Look at the resistance of your meter leads.

If it's an analog meter, parallax introduces errors.

Your meter connection in the circuit can have errors

Any fatigued soldering joints / soldering connections can introduce errors.

You won't reduce the error to 0, but you will soon realize some pitfalls.