HP HP-67 - Manual Problem Solving

Manual problem solving
To get the feel of your HP-67, try a few simple calculations.
First, make sure the slider switches at the top are as follows:
(tap them to change their current setting if needed)
! !
!
To solve: 5 + 6 = 11 , press:!
! ! ! !
You should see 11.00 in your display. This method of
entering calculations, where the numbers are separated with
the ENTER key and the function is selected last, is called
Reverse Polish Notation (RPN), or Postfix entry. It seems a
little odd the first time, but it allows you to enter calculations
without parentheses. For example, if you wanted to divide the
above total by 4 , you would simply press 4, then the divide
key:!
! !
You should see 2.75 now in your display. Intermediate
results are stored automatically when you key in new
numbers. This is how you string calculations together.