A rectangular metal plate measures (14.5 ± 0.1) cm by (6.0 ± 0.1) cm. Find its area with its error.

Step 1. Area. $14.5\ \text{cm} \times 6.0\ \text{cm} = 87.0\ \text{cm}^2$.

Step 2. Relative errors. $\dfrac{0.1\ \text{cm}}{14.5\ \text{cm}} = 0.69\%$ and $\dfrac{0.1\ \text{cm}}{6.0\ \text{cm}} = 1.67\%$; together $2.4\%$.

Step 3. Absolute error. $0.0236 \times 87.0\ \text{cm}^2 = 2.0\ \text{cm}^2$.