HP 33s Scientific manual Setting the Maximum Denominator, Choosing a Fraction Format

„You can select one of three fraction formats.

The next few topics show how to change the fraction display.

Setting the Maximum Denominator

For any fraction, the denominator is selected based on a value stored in the calculator. If you think of fractions as a b/c, then /c corresponds to the value that controls the denominator.

The /c value defines only the maximum denominator used in Fraction–display mode — the specific denominator that's used is determined by the fraction format (discussed in the next topic).

„To set the /c value, press n Œ, where n is the maximum denominator you want. n can't exceed 4095. This also turns on Fraction–display mode.

„To recall the /c value to the X–register, press 1 Œ.

„To restore the default value or 4095, press 0 Œ. (You also restore the default if you use 4095 or greater.) This also turns on Fraction–display mode.

The /c function uses the absolute value of the integer part of the number in the X–register. It doesn't change the value in the LAST X register.

Choosing a Fraction Format

The calculator has three fraction formats. Regardless of the format, the displayed fractions are always the closest fractions within the rules for that format.

„Most precise fractions. Fractions have any denominator up to the /c value, and they're reduced as much as possible. For example, if you're studying math concepts with fractions, you might want any denominator to be possible (/c value is 4095). This is the default fraction format.

„Factors of denominator. Fractions have only denominators that are factors of the /c value, and they're reduced as much as possible. For example, if you're calculating stock prices, you might want to see  + and  + ( /c value is 8 ). Or if the /c value is 12, possible denominators are 2, 3, 4, 6, and 12.

„Fixed denominator. Fractions always use the /c value as the denominator — they're not reduced. For example, if you're working with time measurements, you might want to see  + ( /c value is 60 ).

Fractions 5–5