Make Pickett, USA
Model 510-T, Business and Finance

1. This rule is designed specifically for finance and business calculations. Whilst most of the scales on this rule are standard scales, but with different naming, it does have a few scales that are not standard.
2. The C and CF scales are the same as the C and CF on "standard" rules. The R and RF are the equivalent to the D and DF scales on  "standard" rules. These scales lend themselves to problems of multiplication, division and proportions.
3. In this case C stands for Cost and R for Retail.
4. Two scales which are different are the C% (cost mark-up percent) and R% (retail mark-up percent). These special scales, C% and R%, are unusual in that they run from 0 to 9, they are in effect the values of the C and CI scales minus 1. The picture shown as "use for mark-up" is an example of the C, R and C% scales. With the retail price of 15 (R scale) and the cost price of 12 (C scale)  the cost mark-up is 25% (C% scale) . The picture shown as "use for discount" is an example of the C, R, and R% scales. With a retail price of 75 (R scale) and a cost price of 60 (C scale) the discount is 20% (R% scale).
5. On the back of the rule are three log-log scales for compound interest problems. To cover as wide a range of scales as possible these log-log scales are to the base 10, rather than the more common e (2.718). The lowest value of 1.00232 this is equivalent to a daily rate when the annual rate of interest is 2.3% and enables interest on a daily basis.

Picture 1- Front view
9915-pickett-510-01.jpg (22438 bytes)
Detail - front left
9915-pickett-510-02.jpg (22020 bytes)
Detail - front right
9915-pickett-510-03.jpg (13754 bytes)
Back view
9915-pickett-510-04.jpg (22897 bytes)
Detail - back left
9915-pickett-510-05.jpg (17417 bytes)
Detail - back right
9915-pickett-510-06.jpg (12477 bytes)
Detail - use for mark-up
9915-pickett-510-07.jpg (8686 bytes)
Detail - use for discount
9915-pickett-510-08.jpg (11947 bytes)
Manufacturing date c 1960
Length 10"
Material Metal
Scales RF=DF [ CF, C%, C] R=D, C%
S1=LL00, S2=L01 [ C2=B, L, 1/C=CI, C ] D, S3=LL03
Equivalent standard scale lettering shown in italics.
Cursor Plastic - single line