HP 35s User Manual page 61

by starting with the innermost parentheses (7
as you would with pencil and paper. The keystrokes were
 
If you work the problem from left–to–right, press

This method takes one additional keystroke. Notice that the first intermediate result is
still the innermost parentheses (7
right is that you don't have to use

functions ( and
However, the first method (starting with the innermost parentheses) is often preferred
because:
It takes fewer keystrokes.
It requires fewer registers in the stack.
When using the left–to–right method, be sure that no more
Note
than four intermediate numbers (or results) will be needed at
one time (the stack can hold no more than four numbers).
The above example, when solved left–to–right, needed all registers in the stack at
one point:
Keys:





4 [14 + (7
3). The advantage to working a problem left–to–


).
Display:

_


RPN: The Automatic Memory Stack
3) – 2]
3) and working outward, just
.
to reposition operands for noncommutative
Saves 4 and 14 as intermediate
numbers in the stack.
At this point the stack is full with
numbers for this calculation.
Intermediate result.
Intermediate result.

.
Description:
2-15