Table of Contents
Advertisement
Section 2
Controlling the Display
In the HP-25, numbers in the display normally appear rounded
to only two decimal places. For example, the fixed constant 7,
which is actually in the calculator as 3.141592654, normally
appears in the display as
(unless you tell the calculator
to show you the number rounded to a greater or lesser number
of decimal places).
Although a number is normally shown to only two decimal
places, the HP-25 always computes internally using each num-
ber as a 10-digit mantissa and a two-digit exponent of 10. For
example, when you compute 2 X 3, you see the answer to only
two decimal places:
Press
Display
2 EEE 3
However, inside the calculator all numbers have 10 digit man-
tissas and two-digit exponents of 10. So the calculator actually
calculates using full 10-digit numbers:
2.000000000 x 1Q°°
3.000000000 x 10° [x]
yields an answer that is actually carried to 10 digits:
6.000000000x10°°
e
..
You see iny
. . . but these digits
these digits. . .
are also present.
Display Control Keys
allows numbers to be displayed in fixed decimal point for-
mat, [sci]displays numbers in scientific notation format, and
[Enc] displays numbers in engineering notation, with exponents
of 10 shown in multiples of three (e.g., 103, 105, 109).
D_isplay control alters only the manner in which numbers are
displayed in the HP-25. The actual number itself is not altered
by any ofthe display control keys. No matter what notation you
select, these rounding options affect the display only—the
HP-25 always calculates internally with a full 10-digit number
(multiplied by 10 raised to a two-digit exponent).
25
Advertisement
Table of Contents
