HP HP-21 - Two-Number Functions

For example, to use the one-number function {2 key, you key
in the x-number and press the function. To calculate 1/4, key in
4 (the x-number) and press the [[23 key.
Example: Calculate 1/4:
Press
4
2"
S
)
=
&
<
Now try these other one-number function problems. Remem-
ber, first key in the number, then press the function:
1
55 = [o0s
V2500 =
10° = (Use the [o*]key.)
V3204100 =
log12.58925411 =
Two-Number Functions
Two-number functions are functions that must have two num-
bers present in order for the operation to be performed. For
example, you cannot add, subtract, multiply, or divide unless
there are two numbers present in the calculator, so[+] [=][x]and
(+] are examples of two-number function keys.
Two-number functions work the same way as one-number
functions—that is, the operation occurs when the function key
is pressed. Therefore, both numbers must be in the calculator
before the function key is pressed. To place two numbers into
the calculator and perform an operation:
1. Key in the first number.
. Press to separate the first number from the second. 2
3. Key in the second number.
4. Press the function key to perform the operation.