Actual measurement = 10cm approximated value of measurement = 10.5cm % error = \(\frac{\text{Actual measurement − Approximated}}{\text{Actual measure}}\) × 100 = \(\frac{10 − 10.5}{10}\) × 100 = \(\frac{-0.5}{10}\) × 100 ignore -sign i.e take absolute value = \(\frac{0.5}{10}\) × 100 = 5 %