Transcript Document
Quick Time™ an d a TIFF ( Un compr ess ed) de compr ess or ar e n eed ed to s ee this pic ture . What is the Discipline of Mathematics Education? Essential Maths & Mathematical Essences John Mason 1 Hobart 2007 Quick Time™ an d a TIFF ( Un compr ess ed) de compr ess or ar e n eed ed to s ee this pic ture . Outline Justifying “a problem a day keeps the teacher in play” What mathematics is essential? What is mathematical essence? 2 Grid Movement ((7+3)x2)+3 is a path from 7 to ‘?’. What expression represents the reverse of this path? What values can ‘?’ have: x2 ÷2 ? if exactly one - and one ÷ are used? Max value? Min Value? 7 What about other cells? Does any cell have 0? -7? Does any other cell have 7? -3 3 +3 Characterise ALL the possible values that can appear in a cell Reflections x2 ÷2 ? 7 What variations are possible? What have you gained by -3 +3 working on this task (with colleagues)? What criteria would you use in choosing whether to use this (or any) task? What might be gained by working on (a variant of) this task with learners? Tasks –> Activity –> Experience –> ‘Reflection’ 4 More Disciplined Enquiry What is the point? (Helen Chick) – Outer task & Inner task What is the line? (Steve Thornton) – Narrative for HoD, Head, parents, self What is (the) plain? – What awarenesses? What ‘outcomes’? What is the space? – Domain of related tasks – Dimensions of possible variation; ranges of permissible change 5 Differences 6 1 1 1 1 1 1 7 6 42 2 1 2 1 11 1 1 1 1 1 11 3 2 6 8 7 56 6 24 4 8 Anticipating 1 1 1 1 1 Generalising 4 3 12 2 4 Rehearsing 1 1 1 5 4 20 Checking 1 1 1 1 1 1 1 1 1 Organising 6 5 30 2 3 3 6 4 12 Sketchy Graphs Sketch the graphs of a pair of straight lines whose y-intercepts differ by 2 Sketch the graphs of a pair of straight lines whose x-intercepts differ by 2 Sketch the graphs of a pair of straight lines whose slopes differ by 2 Sketch the graphs of a pair of straight lines meeting all three conditions 7 Chordal Midpoints Where can the midpoint of a chord of your cubic get to? (what is the boundary of the region of mid-points?) What about 1/3 points or 4/3 points? 9 Justifying ‘doing’ maths for oneself and with others Sensitise myself to what learners may be experiencing Refresh my awareness of the movements of my attention Remind myself what it is like to be a learner Experience the type of task I might use with learners 10 Awarenesses Give a family a fish and you feed them for a day Show them how to fish, and you feed them until the stocks run out Obtaining tasks and lesson plans gets you through some lessons … Becoming aware of affordances, constraints and attunements, in terms of mathematical themes, powers & heuristics 11 enables you to promote learning More Or Less Altitude & Area Draw a scalene triangle are a altitude 12 more same more more alt more area more alt same area same Same alt more area less less alt more area less more alt less area same alt less area less alt same area less alt less area More Or Less Rectangles & Area Draw a rectilinear figure which requires at least 4 rectangles in any decomposition are No. of a rectangles more 13 more same less more rects more area more rects same area more rects less area same same rects more area same rects less area fewer fewer rects more area fewer rects fewer rects same area less area How many can have the same More Or Less Percent & Value 50% of something is 20 Value % 14 more same less more 60% of 60 is 36 60% of 30 is 20 40% of 30 is 12 same 50% of 60 is 30 50% of 40 is 20 50% of 30 is 15 less 40% of 60 is 24 40% of 50 is 20 40% of 40 is 16 More Or Less Whole & Part ? of 35 is 21 Part more more 3/4 of 28 is 21 same 6/7 of 35 is 30 less 3/5 of 40 is 24 Whole 15 same 3/5 of 35 is 21 less Magic Square Reasoning 2 2 7 2 1 5 9 8 Sum( 16 6 3 ) – Sum( 4 What other configurations like this give one sum equal to another? Try to describe them in words ) =0 More Magic Square Reasoning Sum( 17 ) – Sum( ) =0 Graphical Awareness 18 Multiplication as Scaling If you stick a pin in Hobart in a map of Australia, and scale the map by a factor of 1/2 towards Hobart And if a friend does the same in Darwin, scaling by 1/2 towards Darwin What will be the difference in the two scaled maps? What if one of you scales by a factor of 2/3 towards Hobart and then by a further 1/2 towards Darwin, while the other scales by 1/2 towards Darwin and then by a further 2/3 towards Hobart? 19 Raise Your Hand When You See … Something which is 2/5 of something; 3/5 of something; 5/2 of something; 5/3 of something; 2/5 of 5/3 of something; 3/5 of 5/3 of something; 5/2 of 2/5 of something; 5/3 of 3/5 of something; 1 ÷ 2/5 of something; 1 ÷ 3/5 of something 20 Essential Conceptual Awarenesses —Choosing the unit —Additive actions —Multiplicative actions —Scaling; multi-ply & many-fold, repetition, lots of; … —Coordinated actions —Angle actions —Combining —Translating —Measuring actions —Comparing lengths; areas; volumes; (unit) —Comparing angles —Discrete-Continuous —Randomness 21 Essential Mathematical-nesses Mathematical Awarenesses underlying topics Movement of Attention Mathematical Themes Mathematical Powers Mathematical Strategies Mathematical Ways of working on these constitute a Dispositions (the) discipline of mathematics education 22 Movement of Attention Gazing (holding wholes) Discerning Details Recognising Relationships Perceiving Properties Reasoning on the Basis of Properties Compare SOLO & van Hiele 23 Mathematical Themes Doing & Undoing Invariance in the midst of Change Freedom & Constraint Extending and Restricting Meaning … 24 Mathematical Powers Imagining & Expressing Specialising & Generalising Conjecturing & Convincing Classifying & Characterising … 25 Mathematical Strategies/Heuristics Acknowledging ignorance (Mary Boole) Changing view point Changing (re)presentation Working Backwards … 26 Mathematical Dispositions Propensity to ‘see’ the world math’ly Propensity to pose problems Propensity to seek structure Perseverence … 27 Essential Pedgaogic Awarenesses Tasks – initiate activity; – activity provides immediate experience; – learning depends on connecting experiences, often through labelling when standing back from the action Mathematics 28 develops from engaging in actions on objects; and those actions becoming objects, … Actions need to become not just things done under instruction or guidance, but choices made by the learner Choices What pedagogic choices are available when constructing/selecting mathematical tasks for learners? What pedagogic choices are available when presenting mathematical tasks to learners? What criteria are used for making those choices? 29 What mathematics is essential? Extensions of teaching-maths – Experience analogously something of what learners experience, but enrich own awareness of connections and utility Extensions of own maths – Experience what it is like to encounter an unfamiliar topic 30 It is only after you come to know the surface of things that you venture to see what is underneath; but the surface of things is inexhaustible (Italo Calvino 1983) 31 Human Psyche Only awareness is educable Only behaviour is trainable Only emotion is harnessable Mental imagery Emotion (affect) Awareness (cognition) Behaviour (enaction) 32 What Can a Teacher Do? Directing learner attention by being aware of structure of own attention (amplifying & editing; stressing & ignoring) Invoking learners’ powers Bringing learners in contact with mathematical heuristics & powers Constructing experiences which, when accumulated and reflected upon, provide opportunity for learners to educate their awareness and train their behaviour through harnessing their emotions. 33 I am grateful to the organisers for affording me the opportunity and impetus to contact, develop and articulate these ideas For this presentation and others and other resources see http://mcs.open.ac.uk/jhm3 34