HP 10s Scientific Calculator - Manual (Page 9)

Notes
To return the calculator to its default settings,
as indicated below press[sm] ^ ^ (Mode) B
in that order. The default settings are:
Calculation mode : COMP
Angle unit: Deg
Exponent display format: Norml
Fraction display: ab/c
Decimal point character: Dot
The mode indicator appears in the upper part of
the display.
Before calculating, check the current mode
setting (COMP, REG or SD) and the angle unit
(Deg, Rad or Grad).
Input Limit
The memory of the calculator can accommodate
79 steps in any one calculation. When you press
a number key or an arithmetic operator key (D ,
B , D , B ) . it occupies one step. Pressing
HorH does not occupy a step. So pressing
[Hi] [^ , for example, takes up only one step.
When you input the 73"^ step of any calculation,
the cursor chonges from "___ " to " ■ " to alert you
to the fact that the capacity of the memory is
almost used up. If what you want to input contains
more than 79 steps, separate the calculation into
two or more smaller calculations and then combine
them os you go.
Press S to recall the previous result, which can
then be used in the next calculation. Please see
the section on Key Memory for more information
about the S key.