WP 34S Owner‘s Manual
Edition 2.2
Page 14 of 103
REAL AND INTEGER OPERATIONS
Most of the commands your WP
34S features are mathematical operations or func-
tions in real domain. ―Real domain‖ means these functions use real numbers like 1 or
2.34 or
or 5.6E-7, and work with them. Please note integer numbers like 8, 9, 10, or
-1 are just a subset of real numbers.
Most real number functions provided operate on one number only
– the number cur-
rently displayed. For example, key in
and press
since 0.7
2
= 0.49
Generally, such functions replace
x
(i.e. the number currently displayed) by the result
f(
x
)
, that‘s all they do.
Some of the most popular mathematical functions, however, operate on two num-
bers. Think of + and
– , for example. On your WP
34S, such a two-number real func-
tion replaces
x
by the result
f(
x
,
y
)
. Now the stack enters the game. Think of it like a
pile of numbers. For subtracting two numbers, you need to know them first, then you
can execute the subtraction. That‘s the essence of RPN.
So having an account of 1,234 US$ and taking 56.7 US$ from it is solved as follows:
enter first number
separates the two numbers in input as in the
very first example above
enter second number
subtract it from the first
By
, the first number
is ―pushed on the stack‖ so a second separate number
can be entered in sequence. The operation
takes its input from the lowest two
stack levels
X
and
Y
but needs only
X
to put its result in. Knowing your WP
34S fea-
tures more than only two stack levels, level
Y
is then filled with the content of the next
higher level, i.e.
z
. This goes on for higher levels, as shown
below
. Please note the
top stack level content is repeated then (since there is nothing else available for fill-
ing). You may use this top level repetition for some nice tricks.
There are also a few three-number real functions included
– e.g. Iβ and %MRR – re-
placing
x
by the result
f(
x, y, z
)
. Then
Y
is filled with
t
and so on, and the content of
the top level is repeated twice.
Some real functions (e.g. DECOMP) operate on one number but return two. Other
operations (like RCL or SUM) do not consume any stack input at all but just return
one or two numbers. Then these extra number(s) will be pushed on the stack, taking
one level per real number.
