TLF ID M009047
This is a 15-page guide for teachers. It continues the development of probability. A careful consideration of outcomes and equally likely outcomes is undertaken. In year 8, students see that these are a special case of finding probabilities of events by summing probabilities of the disjoint (or mutually exclusive) outcomes making up the event. This leads to the concept of complementary events and their probabilities. Students explore, understand and use the language of 'not', 'and', 'at least' and 'or' as connectors in describing events in terms of others. Although the emphasis is on the language, graphical representations of these in either tables or diagrams called Venn diagrams can be of assistance in identification or clarification of expressions in words.