Extra big display
Larger display makes more data easier to read.

2-colour printing
Positive values are shown in black, and negative values are shown in red for easy checking.

Key rollover
Key operations are stored in a buffer, so nothing is lost even during high-speed input.
Cost / Sell / Margin
Calculate the cost, selling price, or margin of profit on an item, given the other two values.

Tax & exchange function
Tax calculation and currency conversion functions.

Regular percent
Regular percentage calculations.

Mark-up / Mark-down
All the mark-up / mark-down capabilities of an adding machine for simplified cost and profit calculations.