Constructing the graph of the tangent function Animation Play

Constructing the image of a triangle in a line Animation Play

Constructing the simplest mathematical model Whiteboard exercise Play

Construction of the angle bisector Whiteboard exercise Play

Constructions Student activity Play

Constructions revisited Simulation Play

Constructions revisited Student activity Play

Counterexamples and proofs Whiteboard exercise Play

Counterexamples and proofs Student activity Play

Deductive reasoning Whiteboard presentation Play

Deductive reasoning Class activity Play

Demonstration or proof? Animation Play

Demonstration or proof? Student activity Play

Different ways of proving Animation Play

Different ways of proving – example as a proof Whiteboard exercise Play

Direct proportionality models Student activity Play

Divisibility by 8 Whiteboard exercise Play

Divisibility by 8 Student activity Play

Elevations Simulation Play

Elevations Student activity Play

Emmanuel's kite Animation Play

Equal numbers – wrong steps in proof Whiteboard exercise Play

Example as a proof Student activity Play

Example as a proof Whiteboard exercise Play

Example of proof Animation Play