HP 33s Scientific manual Representation of Numbers, Negative Numbers, ˜˜

The Representation of Numbers

Although the display of a number is converted when the base is changed, its stored form is not modified, so decimal numbers are not truncated — until they are used in arithmetic calculations.

When a number appears in hexadecimal, octal, or binary base, it is shown as a right–justified integer with up to 36 bits (12 octal digits or 9 hexadecimal digits). Leading zeros are not displayed, but they are important because they indicate a positive number. For example, the binary representation of 12510 is displayed as:

1111101

which is the same as these 36 digits:

000000000000000000000000000001111101

Negative Numbers

The leftmost (most significant or "highest") bit of a number's binary representation is the sign bit; it is set (1) for negative numbers. If there are (undisplayed) leading zeros, then the sign bit is 0 (positive). A negative number is the 2's complement of its positive binary number.

Keys:Display:Description:

546 {x{%}	
^	
{x{}	
˜˜	
{x{}	. )

Enters a positive, decimal number; then converts it to hexadecimal.

2's complement (sign changed).

Binary version; § indicates more digits. Displays the leftmost window; the number is negative since the highest bit is 1.

Negative decimal number.

10–4Base Conversions and Arithmetic