However, if you're breastfeeding exclusively (and that means frequently, day and night), if your baby is younger than 6 months and if your period hasn't resumed, the so-called lactation amenorrhea method can be 98 percent effective in preventing pregnancy.
Then x has a expansion of decimal which terminates. 3) Let x =p/q be a rational number, such that the prime factorization of q is not of the form 25, where n, m are non-negative integers. Then, x has a expansion of decimal which is non-terminating repeating (recurring).
1 One of the oldest is to use the power series expansion of atan(x) = x-x^3/3 + x^5/5 2  - ... together with formulas like pi = 16*atan(1/5) - 4*atan(1/239) . 3  This gives about 1.4 decimals per term. 4  A second is to use formulas coming from Arithmetic-Geometric mean computations.