HP HP-25 User Manual

Hours, Minutes, Seconds
The (to hours, minutes, seconds) key converts decimal
hours to the format of hours, minutes and seconds. To see the
digits for seconds, you should specify FIX 4 display format.
Forexample, to convert 12.56 hours to hours, minutes, seconds:
Press Display
12.56 Decimal hours.
B x4 Sets display format.
[ 1 ] This is read as 12 hours, 33
minutes, 36 seconds.
Conversely, the (to decimal hours) key is used to change
hours, minutes, seconds into decimal hours. For example, to
convert 12 hours, 33 minutes, 36 seconds back into decimal
hours:
Press Display
B 12.5600 Decimal hours.
Hours to hours, minutes, seconds conversion is accurate to 107°
decimal hours.
The [>H] and keys also permit you to change degrees,
minutes, seconds to decimal degrees, and vice versa.
For example, to change 137°45'12" to decimal degrees:
Press Display
137.4512
El *H) Decimal degrees.
The conversion is important because trigonometric functions in
the HP-25 operate on angles in decimal degrees, but not in
degrees, minutes, seconds. In order to calculate any trigono-
metric functions of an angle given in degrees, minutes, seconds,
you must first convert the angle to decimal degrees.
Example: Lovesick sailor Oscar Odysseus dwells on the island
of Tristan da Cunha (37°03" S, 12°18'W), and his sweetheart,
Penelope, lives on the nearest island. Unfortunately for the
course of true love, however, Tristan da Cunha is the most
isolated inhabited spot in the world. If Penelope lives on the
island of St. Helena (15°55’'S, 5°43’'W), use the following

HP HP-25 Specifications

General

Brand	HP
Model	HP-25
Category	Calculator
Language	English