The denominator of the given rational number is 5000.
⇒ 5000 = 23 x 54
It’s seen that, 23 x 54 is of the form 2m x 5n, where m = 3 and n = 4.
∴ \(\frac{257}{5000}\)
= \(\frac{(257\, \times\, 2)}{(5000\, \times\, 2)}\)
= \(\frac{514}{10000}\)
= 0.0514 is its decimal expansion.