HP -01 Owner's Manual page 50

Using the Calculator 48
The following example requires the exchange function to switch the numerator and denominator
to the correct position for division. The division is performed when you press the © key.
To Solve Press Display
(17-12)x4+(10-5 PQPOOOOO .
Store in memory.
Q- 5 Switch numerator
and denominator.
9 4. - The answer.
Both numbers have to be in the calculator before you can switch their positions. Here you must
recall the number from memory first, before pressing the exchange function.