A drink-vending machine dispensing all sorts of weird and wonderful cans of Revolting radish, Warm worm, Rusty nail and the like is the setting of this series of learning objects.

Vile vendor picture.

The 'The vile vendor: questions' learning object asks students to select a word from a bank of five - impossible, unlikely, equal, likely and certain - to describe the chance of the vile vendor serving a particular drink. Feedback is provided for both correct and incorrect responses to reinforce students' understanding of the language and the concept of randomness. After a series of this type of question, students are offered the opportunity to fill the vendor: 'Select the drinks so that it is unlikely you will get a Cabbage drink.' In this mode, as in the previous one, the idea of chance resulting in an outcome different to that of the theoretical probability is explored.

'The vile vendor: go figure' learning object is amenable to a screen reader. It would be a useful tool for teachers to use to discuss probability and its associated language.

'The vile vendor: best guess' is designed to allow users to explore the idea of probability. The user is asked to select the most common drink and then see what happens when the vendor serves a drink. The idea is that the most common drink is also the most likely drink to be served but the random nature of the machine may result in an unlikely event occurring. Feedback supports the idea that understanding mathematical probability can enhance your chances of choosing correctly but that unlikely events can still occur.