HP 33s - Manual (Page 21)

Getting Started 1–5
Keys for Clearing
Key Description
b
Backspace.
„ Keyboard–entry mode:
Erases the character immediately to the left of "_" (the
digit–entry cursor) or backs out of the current menu. (Menus
are described in "Using Menus" on page 1–7.) If the
number is completed (no cursor),
b clears the entire
number.
„ Equation–entry mode:
Erases the character immediately to the left of "¾" (the
equation–entry cursor). If a number entry in your equation
is complete,
b erases the entire number. If the number is
not complete, b erases the character immediately to the
left of "_" (the number–entry cursor). "_" changes back to
"¾" when number entry is complete.
b also clears error messages, and deletes the current
program line during program entry.
‡ Clear or Cancel.
Clears the displayed number to zero or cancels the current
situation (such as a menu, a message, a prompt, a catalog, or
Equation–entry or Program–entry mode).