Section 5: Additional Operating Features 75
Arithmetic Calculations With Constants
Example: At Permex Pipes a certain pipe fitting is packaged in quantities of 15,
75, and 250. If the cost per fitting is $4.38, calculate the cost of each package.
Another method for doing arithmetic calculations with constants is described on
page 173.
Recovering From Errors in Digit Entry
Example: Suppose you want to divide the total annual production for one of
your firm’s products (429,000) by the number of retail outlets (987) in order to
calculate the average number distributed by each outlet. Unfortunately, you
mistakenly key in the number of outlets as 9987 rather than as 987. It’s easy to
correct:
Keystrokes (RPN mode) Display
15\
15.00
Keys first quantity into calculator.
4.38
4.38
Keys unit cost into display.
§
65.70
Cost of a package of 15.
75
75.
Keys second quantity into display.
gF
4.38
Recalls unit cost – which was last
number in display before § was
pressed – into display.
§
328.50
Cost of a package of 75.
250
250.
Keys third quantity into display.
gF
4.38
Recalls unit cost into display again.
§
1,095.00
Cost of a package of 250.
Keystrokes (RPN mode) Display
429000\
429,000.00
9987
9,987.
You haven’t noticed your mistake
yet.
z
42.96
About 43 products per outlet – but
that seems too low!
gF
9,987.00
Recalls to the display the number
that was there before you press z.
You see that you keyed it in wrong.
429000\
429,000.00
Begins the problem over.
987z
434.65
The correct answer.
