Canon P20-DX User Manual page 4

Percent Plus/Minus Key: For performing percentage add-on and discount cal-
culations.
Memory Plus/Equal Key: For obtaining a calculation result and adding the
result automatically to the memory. This key is also used to add a number to
the memory.
Memory Minus/Equal Key: For obtaining a calculation result and subtracting
the result automatically from the memory. This key is also used to subtract a
number from the memory.
Subtotal Recall Memory Key: Used to recall the memory contents. The
memory register is not cleared.
Total Recall Memory Key: Used to recall the memory contents. At the same
time the memory register is cleared.
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