HP 20B User Manual
Page 29
Mathematical Calculations
29
To find a percentage of a given number, enter the number and multiply it by the desired percentage, followed by
=
. For
example, to find 25% of 200, press
200*25%=
to return a result of
50
.
To add or subtract a percentage of a number, enter the first number, followed by
+
or
-
and the percentage followed
by
%
.
Finish your calculation with
=
. For example, to add 10% to 50, press
50+10%=
to
return a result of
55
.
In RPN mode, the
%
key calculates
x
% of the number on Level 2 of the stack, when
x
is the number on Level 1 of the
stack. It does not modify the number on Level 2 of the stack, and thus allows you to perform addition or subtraction after
pressing
%
to add or subtract
x
% from the number.
For example,
200I25%
returns
50
, but
200
is still on Level 2 of the stack, and pressing
-
returns
150
, or 200-25%.