Adjusting The Display Contrast; Keyboard Calculations - HP -28S Manual

The calculator beeps and displays
t'le-mot-
':I
Los t.
The message auto-
matically disappears when you press a key.
If you begin to reset memory but change your mind, continue holding
down [
ON
1
while you press [
DEL
1
(in the top row, next to o::H§]), and
then release @ill. Pressing [
DEL
1
cancels the reset sequence.
Adjusting the Display Contrast
You can adjust the contrast of the display to compensate for various
viewing angles and light intensities.
To adjust the contrast:
1. Press and hold [
ON
I.
2.
Press
G
one or more times to darken the display, or press
G
one or more times to lighten the display.
3. Release [
ON
I.
Keyboard Calculations
Try the following calculation.
(15
+
23) x sin 30°
The basic steps are the same as using paper and pencil. First you'll
calculate 15
+
23, which produces an intermediate result. Next you'll
calculate sin 30°, which produces the other intermediate result. Fi-
nally, you'll combine the intermediate results for the answer.
If you make a mistake while keying in a number, you can:
• Press [!] to erase the last digit you keyed in.
• Press
1
ON
1
to erase all the digits you keyed in.
1: Getting Started 21