Chapter 1 - Exercises and Problems - Page 13: 57

$0.04$%, $0.05$%

We know, Percent uncertainty =$\frac{Uncertainty}{Measured\space value}\times100$% - (1) In here, uncertainty =$ \frac{0.01}{2}$ = 0.005 By using equation (1), Percent uncertainty of 1.27 =$\frac{0.005}{1.27}\times100$% = 0.4% Percent uncertainty of 9.97 =$\frac{0.005}{9.97}\times100$% = 0.05%