I don't fully understand your question, but this can probably this wil help !
Display the first 10 digits of a numeric approximation to [Pi]:
NumberForm[N[Pi], 10] (* 3.141592654 *)
2.Display a number with 3 precise digits and 4 digits to the right of the decimal:
DecimalForm or NumberForm[1.23456, {3, 4}] (* 1.2300 *)
Other option:
N[1/3. // Rationalize, 3] (* 0.333 ) or N[23100/34, 3] (* 67.6 *)
Regards,...Jos