Mantissa Display; Rounding At The Tenth Digit - HP -10C Owner's Handbook Manual

52 Section 4: Display Control
Keystrokes
´^1
´^3
´^2
10*
´•4

Mantissa Display

All numbers held in the calculator's stack and data storage registers are
represented internally as 10-digit mantissas with two-digit exponents. When you
want to view the full 10-digit mantissa of a number held in the X-register, press
´CLEARu and hold the u key. The mantissa of the currently
displayed number will appear and remain in the display until you release the
u key.
Keystrokes
´$
´CLEARu
(hold)

Rounding at the Tenth Digit

As mentioned earlier, your HP-10C holds every value to 10 digits internally,
regardless of the number of places specified in the current •, i, or
^ display setting. The final result of every calculation or series of
calculations is rounded to the tenth digit. For example, π and 2/3 have
nonterminating decimal representations (3.1415926535 ... and 0.6666666666
...). Because the HP-10C can provide only a finite approximation of such
numbers (10 digits), a small error due to rounding can occur in the tenth digit.
This error can be increased through lengthy calculations, but in the majority of
Display
12. -03
12.35 -03
12.3 -03
123 -03
0.1235
Display
3.1416
3141592654
Engineering notation
display. Display is
rounded to one
significant digit after the
leading digit. Power of
10 is multiple of three.
Display is rounded to
third significant digit
after the leading digit.
Display changed to
^2 format.
Decimal shifts to
maintain multiple of
three in exponent.
Usual •4 format.