LEAP Educators’ Conference 2011Developing Thinking Through High School MathematicsYeap Ban HarMarshall Cavendish InstituteSingaporebanhar@sg.marshallcavendish.comPresentation is available on www.banhar.blogspot.com
Link to Keynote LecturesFirst lecture raised the question: “Why is the achievement level eroded when students progress from elementary to high school?”. The second lecture calls for changing mindset.This lecture attempts to answer the question and suggest an alternate way of looking at school mathematics.
IntroductionMathematics is an excellent vehicle for the development and improvement of a person’s intellectual competence…Ministry of Education 2006
Problem SolvingNational Test
 National Test Grade 10 (Secondary 4)	A fly, F, starts at a point with position vector   (i + 12j) cm and crawls across the surface with a velocity of (3i + 2j) cm s-1. At the instant the fly starts crawling, a spider, S, at the point with position vector (85i + 5j) cm, sets off across the surface with a velocity of (-5i + kj) cm s-1, where k is a constant. Given that the spider catches the fly, calculate the value of k.  
Problem SolvingTextbook
Draw a 4-sided polygon.Cut it into triangles.How many triangles can you get?
Example: AlgebraFactoring a quadratic expression.
Algebra Tiles
Example: AlgebraCompleting the square.
Example: AlgebraSolve                      .
Solve                      .
Example: Coordinate GeometryFind the distance between two points.
Problem: Find the distance between points A (2, 3) and B (10, 9).Students working collaboratively on a problem to learn the coordinate geometry topic on distance between points. Traditionally, students were given a formulae to do this. Instead students had to conduct a mini-inquiry to use what they had previously learned.BinaBangsa School, Indonesia
Every group was able to use their previous learning (Pythagoras Theorem) to solve the main problem.BinaBangsa School, Indonesia
BinaBangsa School, IndonesiaLater they were also asked to find points where the distance is a whole number.
Example: CirclesLearning definition and making sense of formulae.
ExampleTo engage pupils in the learning of mathematics.Fuchun Primary School
Task 1 Find the longest distance between two points on a circle.Fuchun Primary School, Singapore
Fuchun Primary School, Singapore
Fuchun Primary School, Singapore
Task 2 Measure circumference and diameter of four circles.Fuchun Primary School, Singapore
Task 3 Draw a circle given that its  circumference is 6 metres.Fuchun Primary School, Singapore
Fuchun Primary School, Singapore
Fuchun Primary School, Singapore
Example: CirclesLearning definition and making sense of formulae.
Area > 2r2
Area < 4r2
2r2 < Area < 4r2
ConclusionMathematics is not just for its content but also for the opportunities to develop generic thinking skills.
Example: Trapeziumacbhd
Example: Trapeziumadcbhda
International Benchmarks
TIMSS 2007 AchievementSingaporeInternationalUSAGrade 8Advanced4062High703115Intermediate886746Low979255Photo: Catholic High School (Primary)
TIMSS 2007 AffectPATMSVMSCMGrade 8High604177Medium203419Low20254Photo: Catholic High School (Primary)

LEAP Educators' Conference 2011, Manila, The Philippines, 11 - 12 February 2011