Let’s Think Secondary Maths, Lesson 2 – Organising teams Overview Thinking Strands: Number and Algebra Learners are challenged to build upon the notion of number carriers they first encountered in Roofs. The basis of the lesson is the systematic organising of teams to play in a league (see video tutorial for details of this due to the ambiguity built into the lesson) to find the total number of games played. In organising teams the move towards the use of expressions comes from the systematic recording/listing of the matches played. The rule developed allows the expression for any number of teams to be written. Aims To recognise the need for systematic listing to spot patterns. To express patterns using the ‘nth’ term and to make predictions based upon this. To explore the use of algebraic symbols in a range of expressions derived from everyday scenarios. Vocabulary Systematic. symbol, expression, algebra, rule, number carrier/holder/variable. In-school resource preparation Materials – Supplied Resource Sheet A: Netball game (Hook) Resource Sheet B: Algebra stories (not produced yet). Materials – Not supplied Large sheets of paper, felt pens. Overview of Activities – please see video tutorial for full details of how to develop this lesson with your class. Hook: This activity can be introduced in a variety of ways (the netball illustration provides a backdrop for the narrative that flows through the lesson). The main task involves the pupils having to work out the total number of games played if 3 schools each play each other and each has to play at home. The ambiguity of not saying whether it is a league or a knock-out tournament challenges the learners to articulate their reasoning and to show their methods. The video tutorial highlights how to manage this aspect of the lesson. This aspect ends with the realisation that 3 schools will play 6 games – please ensure that a range of methods of showing this are present for use in activity 1. Activity 1: Here the class is challenged to use a new method to show how many games will be played if another school is now added. This can be done as a whole class or in pairs. With 5 schools groups of learners can be challenged to come up with the ‘best’ method of showing how many games are played. At this point you may wish to allow them to work on showing 6, 7, 8, 9 or lots of schools. The important point to stress is that there must be a significant period of sharing and debate as pupils air their methods and realise the need for systematic recording to Crown Copyright 2013 highlight the moment when the penny drops i.e. ‘you don’t play yourself’, ‘it’s always one less’. The board/class/large sheets of paper must show a range of methods from simple listing, to highly systematic recording, to repeated addition, to multiplication to facilitate the move towards using expressions by the majority of learners (the video tutorial highlights the way this can be done). The move to generalised number is managed in a similar way to that in Roofs i.e. starting with 10 schools the method to calculate number of games can be shown (10 x 9) until the numbers involved become too large to practically manage without using the multiplication method ie n x n-1. At this point reference can be made back to the use of number carriers and their role in expressing patterns. It may be helpful to stress that we are using expressions to generalise the rule. Activity 2: Use the ‘algebra stories’ note sheet to encourage the learners to develop their understanding of expressions. You may wish to use this activity to explore the use of symbols to stand for numbers and the more formal use of letters within mathematics. This should develop naturally as a consequence of the ideas that come from the note sheet and should not be used to formally teach the use of x and y within formal mathematics notation. End of activity reflection: learners can share and reflect upon and share their own ‘algebra stories’ as they discuss the way we use symbols in expressions and equations to stand for ‘any number’. Notes During joint planning ensure you: Many pupils are familiar with the term ‘algebra’ without understanding the role of number variables and expressions. Many are comfortable with solving simple equations where the ‘unknown’ is fixed – here we are seeking to develop and this often leads them into a simplistic way of thinking about algebra using 1 to 1 correspondence. Think carefully about how to allow the learners to explore this concept themselves without leading them or reinforcing thee misconceptions to bring to the secondary maths classroom. Crown Copyright 2013