If you mean it is not showing everything after the decimal point, you can change that by pressing the [f] key followed by the number of decimal places to display. For example, to restrict it to 2 places, press [f]. If you want to see 4 places, press [f].
To show all possible decimal places, use the sequence [f].
From the manual (http://www.hp.com/ctg/Manual/c00363319.pdf):
"To display a different number of decimal places, press f followed by a digit key (0 through 9) specifying the number of decimal places. In the following examples, notice how the displayed form of the number inside the calculator - 14.87456320 - is rounded to the specified number of digits."
"Although nine decimal places were
specified after f, only eight are
displayed since the display can
show a total of only 10 digits. "
The standard display format, plus the specified number of decimal places, remain in effect until you change them; they are not reset each time the calculator is turned on. However, if Continuous Memory is reset, when the calculator is next turned on numbers will be displayed in the standard display format with two decimal places
If a calculated answer is either too small or too large to be displayed in the standard display format, the display format automatically switches to scientific notation. The display returns to the standard display format for all numbers that can be displayed in that format.