Uncertainty

Percentage error

\begin{equation}error=\frac{No.\,of\,times\,measured*error\,value}{value\,measured}*100\end{equation}

Pipette example

(error: $\pm0.02$) \begin{equation}\frac{1*0.02}{25}*100=\pm8.0*10^{-2}\end{equation}

Balance example

(error: $\pm0.03$) \begin{equation}\frac{3*0.03}{2.13}*100=\pm4.23\end{equation}