28 Section 2: Percentage and Calendar Functions
the base amount inside after you calculate a percentage amount. To calculate a
net amount, simply calculate the percentage amount, then press = or -.
Example: You’re buying a new car that lists for $13,250. The dealer offers you a
discount of 8%, and the sales tax is 6%. Find the amount the dealer is charging
you, then find the total cost to you, including tax.
Percent Difference
In RPN mode, to find the percent difference between two numbers:
1. Key in the base number.
2. Press \ to separate the other number from the base number.
3. Key in the other number.
4. Press à.
If the other number is greater than the base number, the percent difference will
be positive. If the other number is less than the base number, the percent
difference will be negative. Therefore, a positive answer indicates an increase,
while a negative answer indicates a decrease.
If you are calculating a percent difference over time, the base number is typically
the amount occurring first.
Example: Yesterday your stock fell from 58½ to 53¼ per share. What is the
percent change?
The à key can be used for calculations of the percent difference between a
wholesale cost and a retail cost. If the base number entered is the wholesale cost,
Keystrokes (RPN mode) Display
13250\
13,250.00
Keys in the base amount and
separates it from the percentage.
8b
1,060.00
Amount of discount.
-
12,190.00
Base amount less discount.
6b
731.40
Amount of tax (on $12,190).
=
12,921.40
Total cost: base amount less
discount plus tax.
Keystrokes Display
58.5\
58.50
Keys in the base number and
separates it from the other number.
53.25
53.25
Keys in the other number.
à
–8.97
Nearly a 9% decrease.
