Let x = p/q be a rational number, such that the prime factorization of q is of the form 2ⁿ 5^m, where n, m are non-negative integers. Then x has a decimal expansion which terminates.

The denominator 1250 can also be written as 2 × 5⁴.

The maximum power of 2 or 5 in 1250 is 4.

So, it will terminate after 4 places of decimals.