# Keying In Large Numbers; Backspacing - HP 12C Platinum User Manual

Financial calculator.

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.

### Backspacing

While you are entering a number, pressing gÚ deletes the last character you
entered. After performing a calculation, pressing gÚ deletes the current
number.
Keystrokes
(RPN mode)
12345gÚgÚ
.63\
5+
Display
1,781,400,000,000 entered
1.7814 12
in scientific notation.
Display
Correcting removes the 4 and
123.63
5. gÚ clears the most recent
digit entered.
128.63
Clears the calculator line.
0.00