Developed to teach truck drivers how to calculation the number of tie-down straps required for a load. The volvelle, an old-fashioned tool, forces an order to the calculations which breaks old habits and teaches new ones.
The calculation order for the number of tie down straps requires drivers to include the load weight much later in the calculation than seems logical. They needed to break old habits and learn the calculation order. the use of a physical device to teach a new concept is a powerful aid to memory.
And volvelles are a fun tool to use and a bit of fun helps engage students in learning. Volvelles can be made from quite robust materials so that they withstand rough handling, so can be quite useful in dirty environments.
Volvelles are an old fashioned tool that shows the result of calculations. The results are calculated before hand and laid out in a particular and precise pattern on the underneath disc. A top disc with window cut through it overlays the result of the calculations and has a design on it that allows the user to choose inputs and see the result displayed in a window. Slide rules and volvelles do the same job but one is linear and the other is round.