HP 25

54 Function Keys
Percentages
The [JJ key is a two-numb er function that allows you to
compute percentages . To find the percentage of a number ;
1. Key in the base number.
2. PresslmimJ.
3. Key in the number representing percent rate .
4. Press III [JJ .
For examp le, to ca lc ul ate a sa l es tax of 6.5% on a purchase of
$1500:
Press Display
1500 ImimJ 1 1500 .00
6.5 ;::: 16=.5= = =!
III [JJ L.::: 1 9 ~ 7. ~ 50 ~ _
6.5% of $1500 is $97.50.
Base number.
Percent rate .
The answer.
In the above examp l e, when the III [JJ keys are pressed , the
ca lcul ated answer writes over the percentage r ate in the X-
reg
ister , and the base number is preserved in the Y -r egister.
When you pressed III [JJ , the stack contents were changed .. .
. . . from this ...
. . . to this .
T
0.00
T
0.00
Z
0.00
Z
0.00
Y
1500.00 Y
1500.00
X
6.5
X
97 . 50
Since the purchase p ri ce is now in the Y -r egister and the a mount
of tax is in the X-regis ter , the total amount can be obt a ined by
s imply adding:
Press
Display
11597.50
Total of price and sa les tax combined.