Keying In Large Numbers; The Clear Keys - HP 12c User Manual

18 Section 1: Getting Started

Keying in Large Numbers

Since the display cannot show more than 10 digits of a number, numbers greater
than 9,999,999,999 cannot be entered into the display by keying in all the digits
in the number. However, such numbers can be easily entered into the display if the
number is expressed in a mathematical shorthand called "scientific notation." To
convert a number into scientific notation, move the decimal point until there is only
one digit (a nonzero digit) to its left. The resulting number is called the "mantissa"
of the original number, and the number of decimal places you moved the decimal
point is called the "exponent" of the original number. If you moved the decimal
point to the left, the exponent is positive; if you moved the decimal point to the
right (this would occur for numbers less than one), the exponent is negative. To key
the number into the display, simply key in the mantissa, press Æ (enter exponent),
then key in the exponent. If the exponent is negative, press Þ after pressing
Æ.
For example, to key in $1,781,400,000,000, we move the decimal point 12
places to the left, giving a mantissa of 1.7814 and an exponent of 12:
Keystrokes
1.7814Æ12
Numbers entered in scientific notation can be used in calculations just like any
other number.

The CLEAR Keys

Clearing a register or the display replaces the number in it with zero. Clearing
program memory replaces the instructions there with gi00. There are several
clearing operations on the hp 12c, as shown in the table below:
Key(s)
O
fCLEAR²
fCLEARÎ
fCLEARG
fCLEARH
File name: hp 12c_user's guide_English_HDPMBF12E44
Printered Date: 2005/7/29
Display
1.7814 12
Clears:
Display and X-register.
Statistics registers (R through R
1
display.
Program memory (only when pressed in Program mode).
Financial registers.
Data storage registers, financial registers, stack and LAST X
registers, and display.
Page: 18 of 209
Dimension: 14.8 cm x 21 cm
1,781,400,000,000 entered in
scientific notation.
), stack registers, and
6