HP 48G - Manual (Page 30)

Lesson 6: Doing Arithmetic
There are actually two different ways that you can “do" arithmetic on
the HP 48. The stack method is most convenient when you want to
perform immediate calculations involving one or more numbers. The
algebraic method is most convenient when you wish to describe your
calculation as a formula, (so that you can verify it or reuse it) before
evaluating it.
Stack Method
Look at an example of the way t.lie stack works during a calculation.
It works very mucli like the pencil-anfL])aper arithmetic taught in
elementary school. For example, to find the difference of two numbers
(such as 8.9 and 7.2), you first, write them Iroth onto the pairer and
1 h ( a sid3tract:
8.^
'"TT
Using the stack for arithmetic on the HP 48 exactly mirrors the
manual process. Enter the numbers (or
a r g u m e n ts )
first, then perform
the operation.
Example: Subtract 7.2 from 8.9 on the HP 48.
S te p 1 : Enter the numbers. Notice that yon enter numbers in the
same order that you would write them on paper.
8.9 (ENTER) 1 .2 (ENTER) £■: 8.9
1 ■ “3 0
!_■ ____ ____ ____ ____ J* > C.
S te p 2 :
Perform the subtraction. The subtraction operation removes
the objects on the first two stack levels (noting the order)
and returns the difference back to level 1.
0 1: 1.7
3-2 Arithmetic