HP 35s Scientific Calculator - Manual (Page 102)

5-10 Fractions
Fractions in Programs
You can use a fraction in a program just as you can in an equation; numerical
values are shown in their entered form.
When you're running a program, displayed values are shown using Fraction–
display mode if it's active. If you're prompted for values by INPUT instructions, you
may enter fractions. The program’s result is displayed using the current display
format.
A program can control the fraction display using the /c function and by setting and
clearing flags 7, 8, and 9. See "Flags" in chapter 14.
See chapters 13 and 14 for information about working with programs.