Texas Instruments TI Programmable 57 Manual page 16

SECTION 1: BASIC
KEYS AND FUNCTIONS
CLEARING THE CALCULATOR
There are several procedures that allow you to clear various parts of your
calculator, or to clear the entire machine — depending on your needs as
you proceed through a problem.
[CE] The [£8] (clear entry) key clears the last number you entered into
the calculator, as long as that number wasn't followed by a
function or operation key. (So if you accidentally hit a [5] instead
of a [Jin the middle of an entry, just hit (c) and try again.) This
key will also stop the display from flashing if you've created an
error condition in your calculator (we'll say more about this later).
The [€€] key, however, doesn't affect pending operations, what's
stored in the memories, or calculated results.
[INV] — This key sequence clears everything in the machine
except program steps and decimal settings. (Technically, this
doesn't clear the first two registers of the math stack, but this will
seldom be a problem.)