In practice, error can be calculated and applied in one's head, but for reference it is always advisable to record the figures on the chart.
Ekuziqhelaniseni, impazamo ingabalwa okanye isetyenziswe kwintloko, kodwa ukwenzela ukungalibeli okanye ukukhangela, kucetyiswa ukuba ubhale amanani kwitshati.