$312000000 = 3.12 \times 10^8 \approx 3 \times 10^8$
$ \varepsilon = \frac{3.12\times 10^8 - 3 \times 10^8}{3.12 \times 10^8} = 0.04$
--
$0.45714571 = 4571.4571 \times 10^{-4} \approx 4571\times 10^{-4}$
$ \varepsilon = \frac{4571.4571 \times 10^{-4} - 4571 \times 10^{-4}}{4571.4571 \times 10^{-4}} = 0.0001$
--
$5/3 = 1.66666666... = 166666.66 \times 10^{-5} \approx = 166667 \times 10^{-5}$
$ \varepsilon = \frac{5/3 - 166667 \times 10^{-5}}{5/3} = 0.000002$
Noemi