Reply to post: I had a similar idea years ago

I had a similar idea years ago

I had a similar idea years ago, for shops to rip off customers.

In the 1990s, shops were still weighing loose goods in pounds, ounces and eighths of an ounce, using electronic scales. This means you, as a customer, can't do a quick calculation of how much you should be paying for your fruit and veg, as you would with goods weighed in kilos (which calculation is simply the product of two decimal fractions -- specific price in £/kg * mass in kg -- and can be performed using a simple calculator) -- there are two base changes in one of the multiplicands, and the food will be off the scales and in the bag before you can verify the price.

It would have been trivially easy to determine when the calculation is not an easy one (for instance, anything involving a whole number of ounces is an easy calculation) and increase the price charged accordingly. As long as the error is not outrageous, it is unlikely to be noticed. The scale manufacturer can be fairly sure that a weight corresponding to a whole number of ounces, or the equivalent of a round number of grams, is a calibration weight; and if so, give a true reading.

A few pence on every single transaction in a busy supermarket adds up to a lot .....