To close the calculator, fold the two sides together and press until you
hear a click.
You can fold back the left-hand side of the caI,.::ulator until it is back-
to-back with the right-hand keyboard. This is handy for field work-
when you want to hold the calculator in one hand and operate it with
the other-or to save space on a desk.
Locating the Battery Door and Printer Port
With the calculator open, note the location of the battery door and the
The HP-28S is powered by three N-cell alkaline batteries. Batteries
are included with the calculator. If the batteries are not already in-
stalled, follow the instructions that start on page 286.
1: Getting Started